Thanks for the suggestions, guys. I'll investigate the heli-coil situation to see if there are ones small enough, but i think ultimately i'm going to find a good gunsmith to do the work.
I'm the 3rd (at least) owner of my M629-1. The previous owner didn't shoot it at all and did not have anything done to the pistol. I have shot just under 20 rounds out of it. There has been trigger work done, with a very light single-action trigger pull as a result. I found a problem today...