Visual Studio will not display two assemblies of same name even if the version of the assemblies are different. If you want multiple versions of the same assembly to appear in the Visual Studio list of installed assemblies, provide a different name for each version of the assembly, like in your case MyLibrary.1.0.0.1.dll and MyLibrary.1.0.0.2.dll.
EDIT: One more way of adding same name assemblies to the dialog box is by placing the assemblies in two separate folders and adding those folders to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\AssemblyFolders
key.