Assembly Load Error

Hi

I have a custom login page deployed as a WSP package and built with .NET Framework v2 for SharePoint 2010.  The installation and deployment of the WSP contents into SharePoint 2013 all executed as expected.

I reference my custom login page when creating a new web application (I've created a site also).  However when I attempt to invoke the custom login page I get an error:

I get the error: could not load file or assembly Microsoft.SharePoint.Administration, Version 15.0.0.0, culture=neutral.......or one of its dependencies

The custom login page has a reference to the version 14.0.0.0 of the above assembly, I'm assuming the assembly redirects are in part causing the error.

How do I get me login page to load in a SharePoint 2013 environment?

Thanks