I am not a gunsmith. To advance their timing I have replaced the hands on a few short action S&Ws with over size hands. None required fitting. The "fitting" that might be necessary is widening the hand slot through the recoil shield. You'd file the side that the hand does not bear against. None of the over size hands I installed advanced the timing as much I wanted so refiling the ratchet for an oversize hand that is too tight is not something I'd worry about. I doubt you can find an oversize hand that fat. I'm even more skeptical that you could find any over size hand for for a long action S&W.

For the few here who do not know S&W changed their revolvers from long action to short action about 1948. Model 1917s do not have a hammer block safety. After WW I the hands changed to one with a cam that moved a hammer block safety out of the way. Hands were changed again during WW II when the modern hammer block safety was introduced.

Member Hondo44 has posted that he has had success peening hands and made it sound easy. Hopefully he'll provide some instruction.