In general it is not possible to have more than one version of OpenAccess assemblies in GAC. Could you please specify what is the exact problem which you have to solve and which are the assemblies that you want to have with different versions? We might be able to provide you with a solution.
I am looking forward to hearing from you.
the Telerik team
Telerik OpenAccess ORM Meets ASP.NET Web API. Read more.