I have an Umbraco user control written in VS 2005, let's call it "myusercontrol"

This VS project references Umbraco assemblies businesslogic.dll, cms.dll, umbraco.DataLayer.dll, umbraco.dll.

Copies of these assemblies were pulled from an older Umbraco install onto a developer machine and referenced in the VS project.

When I build that project, I take "myusercontrol.dll" (and an .ascx file) and put them in my production bin and usercontrol folder, respectively.

What I'm wondering is, does "myusercontrol.dll" contain all the code from the other Umbraco assemblies in the VS project? The reason I ask is because I used this user-control in a newer build of Umbraco whose assemblies were build against a new version of the .NET Framework. I DID NOT copy over the Umbraco assemblies from the VS project (which are older) into the production bin.

So, does my control still work because all the referenced Umbraco assemblies that "myusercontrol.dll" needs are compiled into "myusercontrol.dll" ?

Or,

Does the control just use the Umbraco assemblies with the same name in the production bin (which are newer and built against a newer .NET framework) and I have lucked out?

Thanks.