The upgrade that I saw for the original TS appeared to be simply the removal of the side mount lug and welding on of the standard mount lug. The barrel band seems to be unique to the original TS series. That will probably make that stock difficult to find.

I'm getting my info from "Italyicon's Battle Rifle" by the way. A few copies may still be available. The authors are Russ Atendell and Steve Woodrum.