diff --git a/src/Umbraco.Core/ContentVariationExtensions.cs b/src/Umbraco.Abstractions/ContentVariationExtensions.cs
similarity index 98%
rename from src/Umbraco.Core/ContentVariationExtensions.cs
rename to src/Umbraco.Abstractions/ContentVariationExtensions.cs
index bdcf300f3f..f3e8943172 100644
--- a/src/Umbraco.Core/ContentVariationExtensions.cs
+++ b/src/Umbraco.Abstractions/ContentVariationExtensions.cs
@@ -44,7 +44,7 @@ namespace Umbraco.Core
         /// <summary>
         /// Determines whether the property type is invariant.
         /// </summary>
-        public static bool VariesByNothing(this PropertyType propertyType) => propertyType.Variations.VariesByNothing();
+        public static bool VariesByNothing(this IPropertyType propertyType) => propertyType.Variations.VariesByNothing();
 
         /// <summary>
         /// Determines whether the property type varies by culture.
diff --git a/src/Umbraco.Core/Models/ContentBase.cs b/src/Umbraco.Abstractions/Models/ContentBase.cs
similarity index 98%
rename from src/Umbraco.Core/Models/ContentBase.cs
rename to src/Umbraco.Abstractions/Models/ContentBase.cs
index e5adddad72..59693efe53 100644
--- a/src/Umbraco.Core/Models/ContentBase.cs
+++ b/src/Umbraco.Abstractions/Models/ContentBase.cs
@@ -44,7 +44,7 @@ namespace Umbraco.Core.Models
         /// <summary>
         /// Initializes a new instance of the <see cref="ContentBase"/> class.
         /// </summary>
-        protected ContentBase(string name, int parentId, IContentTypeComposition contentType, PropertyCollection properties, string culture = null)
+        protected ContentBase(string name, int parentId, IContentTypeComposition contentType, IPropertyCollection properties, string culture = null)
             : this(name, contentType, properties, culture)
         {
             if (parentId == 0) throw new ArgumentOutOfRangeException(nameof(parentId));
@@ -54,14 +54,14 @@ namespace Umbraco.Core.Models
         /// <summary>
         /// Initializes a new instance of the <see cref="ContentBase"/> class.
         /// </summary>
-        protected ContentBase(string name, IContentBase parent, IContentTypeComposition contentType, PropertyCollection properties, string culture = null)
+        protected ContentBase(string name, IContentBase parent, IContentTypeComposition contentType, IPropertyCollection properties, string culture = null)
             : this(name, contentType, properties, culture)
         {
             if (parent == null) throw new ArgumentNullException(nameof(parent));
             SetParent(parent);
         }
 
-        private ContentBase(string name, IContentTypeComposition contentType, PropertyCollection properties, string culture = null)
+        private ContentBase(string name, IContentTypeComposition contentType, IPropertyCollection properties, string culture = null)
         {
             ContentType = contentType?.ToSimple() ?? throw new ArgumentNullException(nameof(contentType));
 
@@ -84,7 +84,7 @@ namespace Umbraco.Core.Models
         [IgnoreDataMember]
         public ISimpleContentType ContentType { get; private set; }
 
-        internal void ChangeContentType(ISimpleContentType contentType)
+        public void ChangeContentType(ISimpleContentType contentType)
         {
             ContentType = contentType;
             ContentTypeId = contentType.Id;
diff --git a/src/Umbraco.Abstractions/Models/ContentExtensions.cs b/src/Umbraco.Abstractions/Models/ContentExtensions.cs
new file mode 100644
index 0000000000..5fd5e576b8
--- /dev/null
+++ b/src/Umbraco.Abstractions/Models/ContentExtensions.cs
@@ -0,0 +1,19 @@
+using System.Linq;
+
+namespace Umbraco.Core.Models
+{
+    public static class ContentExtensions
+    {
+        public static bool IsAnyUserPropertyDirty(this IContentBase entity)
+        {
+            return entity.Properties.Any(x => x.IsDirty());
+        }
+
+        public static bool WasAnyUserPropertyDirty(this IContentBase entity)
+        {
+            return entity.Properties.Any(x => x.WasDirty());
+        }
+
+
+    }
+}
diff --git a/src/Umbraco.Abstractions/Models/ContentRepositoryExtensions.cs b/src/Umbraco.Abstractions/Models/ContentRepositoryExtensions.cs
new file mode 100644
index 0000000000..8bc41e1190
--- /dev/null
+++ b/src/Umbraco.Abstractions/Models/ContentRepositoryExtensions.cs
@@ -0,0 +1,58 @@
+using System;
+using System.Linq;
+using Umbraco.Core.Exceptions;
+
+namespace Umbraco.Core.Models
+{
+    public static class ContentRepositoryExtensions
+    {
+        public static void SetCultureInfo(this IContentBase content, string culture, string name, DateTime date)
+        {
+            if (name.IsNullOrWhiteSpace())
+                throw new ArgumentNullOrEmptyException(nameof(name));
+
+            if (culture.IsNullOrWhiteSpace())
+                throw new ArgumentNullOrEmptyException(nameof(culture));
+
+            content.CultureInfos.AddOrUpdate(culture, name, date);
+        }
+
+        /// <summary>
+        /// Updates a culture date, if the culture exists.
+        /// </summary>
+        public static void TouchCulture(this IContentBase content, string culture)
+        {
+            if (culture.IsNullOrWhiteSpace()) return;
+            if (!content.CultureInfos.TryGetValue(culture, out var infos)) return;
+            content.CultureInfos.AddOrUpdate(culture, infos.Name, DateTime.Now);
+        }
+
+        /// <summary>
+        /// Used to synchronize all culture dates to the same date if they've been modified
+        /// </summary>
+        /// <param name="content"></param>
+        /// <param name="date"></param>
+        /// <remarks>
+        /// This is so that in an operation where (for example) 2 languages are updates like french and english, it is possible that
+        /// these dates assigned to them differ by a couple of Ticks, but we need to ensure they are persisted at the exact same time.
+        /// </remarks>
+        public static void AdjustDates(this IContent content, DateTime date)
+        {
+            foreach (var culture in content.PublishedCultures.ToList())
+            {
+                if (!content.PublishCultureInfos.TryGetValue(culture, out var publishInfos))
+                    continue;
+
+                // if it's not dirty, it means it hasn't changed so there's nothing to adjust
+                if (!publishInfos.IsDirty())
+                    continue;
+
+                content.PublishCultureInfos.AddOrUpdate(culture, publishInfos.Name, date);
+
+                if (content.CultureInfos.TryGetValue(culture, out var infos))
+                    SetCultureInfo(content, culture, infos.Name, date);
+            }
+        }
+    }
+
+}
diff --git a/src/Umbraco.Core/Models/SimpleContentType.cs b/src/Umbraco.Abstractions/Models/SimpleContentType.cs
similarity index 100%
rename from src/Umbraco.Core/Models/SimpleContentType.cs
rename to src/Umbraco.Abstractions/Models/SimpleContentType.cs
diff --git a/src/Umbraco.Core/PublishedModelFactoryExtensions.cs b/src/Umbraco.Abstractions/PublishedModelFactoryExtensions.cs
similarity index 100%
rename from src/Umbraco.Core/PublishedModelFactoryExtensions.cs
rename to src/Umbraco.Abstractions/PublishedModelFactoryExtensions.cs
diff --git a/src/Umbraco.Core/ContentExtensions.cs b/src/Umbraco.Core/ContentExtensions.cs
index 07fc2757ea..f9d06b70a3 100644
--- a/src/Umbraco.Core/ContentExtensions.cs
+++ b/src/Umbraco.Core/ContentExtensions.cs
@@ -328,15 +328,7 @@ namespace Umbraco.Core
             return entity.Properties.Where(x => x.IsDirty()).Select(x => x.Alias);
         }
 
-        public static bool IsAnyUserPropertyDirty(this IContentBase entity)
-        {
-            return entity.Properties.Any(x => x.IsDirty());
-        }
 
-        public static bool WasAnyUserPropertyDirty(this IContentBase entity)
-        {
-            return entity.Properties.Any(x => x.WasDirty());
-        }
 
         #endregion
     }
diff --git a/src/Umbraco.Core/Models/ContentRepositoryExtensions.cs b/src/Umbraco.Core/Models/ContentRepositoryExtensions.cs
index f9efc60142..db557e1905 100644
--- a/src/Umbraco.Core/Models/ContentRepositoryExtensions.cs
+++ b/src/Umbraco.Core/Models/ContentRepositoryExtensions.cs
@@ -88,7 +88,7 @@ namespace Umbraco.Core.Models
             {
                 content.CultureInfos.Clear();
                 content.CultureInfos = null;
-            }                
+            }
 
             if (culture == null || culture == "*")
                 content.Name = other.Name;
@@ -112,32 +112,7 @@ namespace Umbraco.Core.Models
             content.PublishCultureInfos.AddOrUpdate(culture, name, date);
         }
 
-        /// <summary>
-        /// Used to synchronize all culture dates to the same date if they've been modified
-        /// </summary>
-        /// <param name="content"></param>
-        /// <param name="date"></param>
-        /// <remarks>
-        /// This is so that in an operation where (for example) 2 languages are updates like french and english, it is possible that
-        /// these dates assigned to them differ by a couple of Ticks, but we need to ensure they are persisted at the exact same time.
-        /// </remarks>
-        public static void AdjustDates(this IContent content, DateTime date)
-        {
-            foreach (var culture in content.PublishedCultures.ToList())
-            {
-                if (!content.PublishCultureInfos.TryGetValue(culture, out var publishInfos))
-                    continue;
 
-                // if it's not dirty, it means it hasn't changed so there's nothing to adjust
-                if (!publishInfos.IsDirty())
-                    continue; 
-                
-                content.PublishCultureInfos.AddOrUpdate(culture, publishInfos.Name, date);
-
-                if (content.CultureInfos.TryGetValue(culture, out var infos))
-                    SetCultureInfo(content, culture, infos.Name, date);
-            }
-        }
 
         // sets the edited cultures on the content
         public static void SetCultureEdited(this IContent content, IEnumerable<string> cultures)
@@ -151,17 +126,6 @@ namespace Umbraco.Core.Models
             }
         }
 
-        public static void SetCultureInfo(this IContentBase content, string culture, string name, DateTime date)
-        {
-            if (name.IsNullOrWhiteSpace())
-                throw new ArgumentNullOrEmptyException(nameof(name));
-
-            if (culture.IsNullOrWhiteSpace())
-                throw new ArgumentNullOrEmptyException(nameof(culture));
-
-            content.CultureInfos.AddOrUpdate(culture, name, date);
-        }
-
         /// <summary>
         /// Sets the publishing values for names and properties.
         /// </summary>
@@ -249,7 +213,7 @@ namespace Umbraco.Core.Models
                 // one single culture
                 keepProcessing = content.ClearPublishInfo(culture);
             }
-            
+
 
             if (keepProcessing)
             {
@@ -288,14 +252,6 @@ namespace Umbraco.Core.Models
             return removed;
         }
 
-        /// <summary>
-        /// Updates a culture date, if the culture exists.
-        /// </summary>
-        public static void TouchCulture(this IContentBase content, string culture)
-        {
-            if (culture.IsNullOrWhiteSpace()) return;
-            if (!content.CultureInfos.TryGetValue(culture, out var infos)) return;
-            content.CultureInfos.AddOrUpdate(culture, infos.Name, DateTime.Now);
-        }
+
     }
 }
diff --git a/src/Umbraco.Core/Models/Media.cs b/src/Umbraco.Core/Models/Media.cs
index 002611c09c..452bb615d1 100644
--- a/src/Umbraco.Core/Models/Media.cs
+++ b/src/Umbraco.Core/Models/Media.cs
@@ -27,7 +27,7 @@ namespace Umbraco.Core.Models
         /// <param name="parent">Parent <see cref="IMedia"/> object</param>
         /// <param name="contentType">MediaType for the current Media object</param>
         /// <param name="properties">Collection of properties</param>
-        public Media(string name, IMedia parent, IMediaType contentType, PropertyCollection properties)
+        public Media(string name, IMedia parent, IMediaType contentType, IPropertyCollection properties)
             : base(name, parent, contentType, properties)
         { }
 
@@ -48,7 +48,7 @@ namespace Umbraco.Core.Models
         /// <param name="parentId">Id of the Parent IMedia</param>
         /// <param name="contentType">MediaType for the current Media object</param>
         /// <param name="properties">Collection of properties</param>
-        public Media(string name, int parentId, IMediaType contentType, PropertyCollection properties)
+        public Media(string name, int parentId, IMediaType contentType, IPropertyCollection properties)
             : base(name, parentId, contentType, properties)
         { }
 
diff --git a/src/Umbraco.Core/Umbraco.Core.csproj b/src/Umbraco.Core/Umbraco.Core.csproj
index 61a657732d..10dc253789 100755
--- a/src/Umbraco.Core/Umbraco.Core.csproj
+++ b/src/Umbraco.Core/Umbraco.Core.csproj
@@ -203,6 +203,7 @@
     <Compile Include="Models\Identity\UserLoginInfoWrapper.cs" />
     <Compile Include="Models\Language.cs" />
     <Compile Include="Models\Macro.cs" />
+    <Compile Include="Models\Media.cs" />
     <Compile Include="Models\Membership\UserGroup.cs" />
     <Compile Include="Models\Membership\UserGroupExtensions.cs" />
     <Compile Include="Models\ObjectTypes.cs" />
@@ -222,7 +223,6 @@
     <Compile Include="PropertyEditors\Validators\DelimitedValueValidator.cs" />
     <Compile Include="PropertyEditors\Validators\RegexValidator.cs" />
     <Compile Include="PropertyEditors\Validators\RequiredValidator.cs" />
-    <Compile Include="PublishedContentExtensions.cs" />
     <Compile Include="Persistence\Dtos\PropertyTypeCommonDto.cs" />
     <Compile Include="Persistence\Factories\MacroFactory.cs" />
     <Compile Include="Persistence\Repositories\Implement\ContentTypeCommonRepository.cs" />
@@ -234,7 +234,7 @@
     <Compile Include="PropertyEditors\PropertyValueConverterCollection.cs" />
     <Compile Include="PropertyEditors\PropertyValueConverterCollectionBuilder.cs" />
     <Compile Include="PropertyEditors\VoidEditor.cs" />
-    <Compile Include="PublishedModelFactoryExtensions.cs" />
+    <Compile Include="PublishedContentExtensions.cs" />
     <Compile Include="Serialization\JsonNetSerializer.cs" />
     <Compile Include="Services\Changes\ContentTypeChange.cs" />
     <Compile Include="Services\Changes\ContentTypeChangeExtensions.cs" />
@@ -250,7 +250,6 @@
     <Compile Include="Sync\RefreshInstructionEnvelope.cs" />
     <Compile Include="TypeExtensions.cs" />
     <Compile Include="TypeLoaderExtensions.cs" />
-    <Compile Include="ContentVariationExtensions.cs" />
     <Compile Include="IO\MediaPathSchemes\CombinedGuidsMediaPathScheme.cs" />
     <Compile Include="IO\MediaPathSchemes\OriginalMediaPathScheme.cs" />
     <Compile Include="IO\MediaPathSchemes\TwoGuidsMediaPathScheme.cs" />
@@ -315,7 +314,6 @@
     <Compile Include="Models\ContentTagsExtensions.cs" />
     <Compile Include="Models\PathValidationExtensions.cs" />
     <Compile Include="Models\PropertyTagsExtensions.cs" />
-    <Compile Include="Models\SimpleContentType.cs" />
     <Compile Include="PackageActions\AllowDoctype.cs" />
     <Compile Include="PackageActions\PublishRootDocument.cs" />
     <Compile Include="Packaging\CompiledPackageXmlParser.cs" />
@@ -405,7 +403,6 @@
     <Compile Include="Migrations\Upgrade\Upgrader.cs" />
     <Compile Include="Migrations\Upgrade\V_8_0_0\DropMigrationsTable.cs" />
     <Compile Include="Models\Content.cs" />
-    <Compile Include="Models\ContentBase.cs" />
     <Compile Include="ContentExtensions.cs" />
     <Compile Include="Models\ContentType.cs" />
     <Compile Include="Models\ContentTypeBase.cs" />
@@ -414,7 +411,6 @@
     <Compile Include="Models\GridValue.cs" />
     <Compile Include="Models\Identity\BackOfficeIdentityUser.cs" />
     <Compile Include="Models\Identity\IdentityUser.cs" />
-    <Compile Include="Models\Media.cs" />
     <Compile Include="Models\MediaExtensions.cs" />
     <Compile Include="Models\MediaType.cs" />
     <Compile Include="Models\Member.cs" />