GunNut,
If the S&W telepone person told you there was no warrantee before 1992, they are full of CRAP!
I used to chat regularly with the people at t6he West Coast S&W Warranty Center in Monrovia, California, and they uniformly agreed that S&W had superb customer support and warranty services. This was up to the middle-late 1980's period. Police departments sent all their warranty service stuff there, and they also handled the S&W recalls and reworks for the problems with M19, M66, M29 revolvers, and all the recalls and improvements for the M39/M59 series pistols.
A broken hammer pivot pin is obviously a "manufacturing defect" and should be so honored. They charged you $129 for pressing it out and pressing in a replacemnt pin? That's OUTRAGEOUS! If this is the S&W that has come back, we should have nothing to do with it!