Dan, you probably know if you get the new hand that you'll need to get the Dremel out and probably take some off and shape it to the timing.
I've done a couple of Rugers, and they both needed fitting, which is OK too. How's the ratchets look on the cylinder side?
Nearly in all cases I've seen the wear & damage to single actions like that were due to someone playing "Hop A Long" and spinning the cylinder and slamming it shut, or too much "eddie fast gun" play with fanning, and the like... 
I love the guys that think you have to drive a magazine home with a sharp rap with the palm of your hand, too... 
Pure Hollywood theatrics....unless they like damaging their expensive handguns.
Barry
