@Sivan Yes, Ultimate Unwrap 3D works sometimes to read the animation correctly. It's unfortunate this format seems so diverse that no one converter can parse it correctly!

@ChaosCoder If I understand correctly, the skins on that website are simply re-skinnings of the original hand or gun models from the game itself produced by Valve. In a commercial application, even a mention would not be legal without Valve's permission.

@PadMalcom Some of their models seem to work and others do not. Perhaps they were not all cleanly made or had a problem in export.