asp.net Swashbuckle integration causes "Could not load file or assembly 'System.Web.Http, Version=4.0.0.0"

I wish to add Swagger to my asp.net REST service using Swashbuckle as outlined here.

I went through all the steps, and since I am using Owin I have both Swashbuckle and Swashbuckle.Core nugets installed.

However, when I run, and navigate to http://localhost/myapp/swagger I get the following error..

Could not load file or assembly 'System.Web.Http, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35

I have version 5.2.4.01 of this DLL so I added the following redirects

  <dependentAssembly>
    <assemblyIdentity name="System.Web.Http" publicKeyToken="31bf3856ad364e35" culture="neutral" />
    <bindingRedirect oldVersion="4.0.0.0" newVersion="5.2.4.0" />
  </dependentAssembly>

  <dependentAssembly>
    <assemblyIdentity name="System.Net.Http.Formatting" publicKeyToken="31bf3856ad364e35" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-5.1.0.0" newVersion="5.2.4.0" />
  </dependentAssembly>

I also added the System.Net.Http.Formatting redirect as I saw this mentioned in another post (but it made no difference)

I still get an error as below...

    Assembly manager loaded from:  C:\Windows\Microsoft.NET\Framework64\v4.0.30319\clr.dll
    Running under executable  c:\windows\system32\inetsrv\w3wp.exe
    --- A detailed error log follows. 

    === Pre-bind state information ===
    LOG: DisplayName = System.Web.Http, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35
     (Fully-specified)
    LOG: Appbase = file:///D:/dev/myapp/trunk/myapp/
    LOG: Initial PrivatePath = D:\dev\myapp\trunk\myapp\bin
    Calling assembly : Swashbuckle.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=cd1bb07a5ac7c7bc.
    ===
    LOG: This bind starts in default load context.
    LOG: Using application configuration file: D:\dev\myapp\trunk\myapp\web.config
    LOG: Using host configuration file: C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet.config
    LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework64\v4.0.30319\config\machine.config.
    LOG: Redirect found in application configuration file: 4.0.0.0 redirected to 5.2.3.0.
    LOG: Post-policy reference: System.Web.Http, Version=5.2.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35
    LOG: Attempting download of new URL file:///C:/Windows/Microsoft.NET/Framework64/v4.0.30319/Temporary ASP.NET Files/myappdev/0d9cef3e/aedd2787/System.Web.Http.DLL.
    LOG: Attempting download of new URL file:///C:/Windows/Microsoft.NET/Framework64/v4.0.30319/Temporary ASP.NET Files/myappdev/0d9cef3e/aedd2787/System.Web.Http/System.Web.Http.DLL.
    LOG: Attempting download of new URL file:///D:/dev/myapp/trunk/myapp/bin/System.Web.Http.DLL.
    WRN: Comparing the assembly name resulted in the mismatch: Build Number
    ERR: Failed to complete setup of assembly (hr = 0x80131040). Probing terminated.

I can see it is trying to use the redirected file, and I have check this file is in my bin folder, but, as above, it still does not work.

I have the following included my packages.config...

      ...
      <package id="Microsoft.AspNet.Cors" version="5.2.4" targetFramework="net47" />
      <package id="Microsoft.AspNet.WebApi" version="5.2.4" targetFramework="net47" />
      <package id="Microsoft.AspNet.WebApi.Client" version="5.2.4" targetFramework="net47" />
      <package id="Microsoft.AspNet.WebApi.Core" version="5.2.4" targetFramework="net47" />
      <package id="Microsoft.AspNet.WebApi.Cors" version="5.2.4" targetFramework="net47" />
      <package id="Microsoft.AspNet.WebApi.Owin" version="5.2.4" targetFramework="net47" />
      <package id="Microsoft.AspNet.WebApi.Tracing" version="5.2.4" targetFramework="net47" />
      <package id="Microsoft.AspNet.WebApi.WebHost" version="5.2.4" targetFramework="net47" /> 
      ...
      <package id="Swashbuckle" version="5.6.0" targetFramework="net47" />
      <package id="Swashbuckle.Core" version="5.6.0" targetFramework="net47" />
      ...

Does anyone have any suggestions on what else I can try here?

Thanks in advance!