Very interresting. I do essentially the same thing to my 1911's including stoning the sear and hammer hooks. What I do not know how to do is to set the timing. I could heat the hand, draw it and then file and polish to set it. But I have no idea if that is the way to do it. Also if I heat the hand to draw it, the temper in the hand spring would be gone, ergo requiring hand spring removal. That along with modifying the bolt would set the timing, drop the bolt into the groove so that when the hand pushes the cyl to where it needs the bolt drops firmly in place. But if a bolt drops to early, I see no real way to correct that without a new bolt and or hammer cam. I generally make my own coil springs, but with the after market availability of main and bolt springs, I do not see the need for me to go there. Here is my dilema. If I stone the trigger it effectively will allow the hammer to go to full cock before the cyl is fully rotated into position. Therefore the hand becomes too short. If I heat the hand to draw it, is it tempered or surface hardened? I have looked at the hand spring and realize that one of these days I will need to replace one, I just have not wanted to tinker with it until I have read enough and talked to others about how to do. The 1911 has so much published information about ways to tune it that with a little mechanical ability, there is nothing on that gun I would not attempt from plunger tube replacement to cutting hammer hooks. Wish I could find this type of information on the SAA's.
Now here is a question for you. Third gen colts do not have base pin bushings. Now this is a what if question, I do not have one yet. If the cylinder becomes sloppy on the pin, one can simply replace it with an oversize pin and ream to fit. Could the cylinder be mounted in my mill, the center of the pin hole determined, and then cut it for a base pin bushing? I see the cylinder indexing slots are a little different, but if it would accept a base pin bushing, would that not be a better way to go? Now one would not have to through cut the cylinder for the full length base pin bushing, but leave 0.020 or so on the hand end of the cyulinder and fit a bushing to it that way. My curiosity is piqued here, so I will ask a lot of questions of someone with more knowledge than I have.