I took the backstrap and trigger guard off today. I have a brass trigger guard from a Navy Colt replica, and a backstrap from a Colt SAA. I trial fitted these to my Hy Hunter Western Six Shooter and they seemed to fit up faily well. The mainspring screw and backstrap/trigger guard screw from the Hy Hunter won't work with these pieces. Probably can get Uberti screws to work. Original grips are not compatible, but with fake stag plastic, who cares?
The hammer/firing pin assembly is another thing I want to tackle:
Doesn't seem to be too big a job to do that from what I understand.