Those who post "where can I find a" ........... for my vintage Smith Revolver should DEFINITELY attend some local gun shows. Every single time I go to one I find guys there with organized parts bins full of hard to find parts. Hammers, Triggers, Springs, Grips, Screws etc. Many are take-offs but you can still find new parts too. Prices aren't cheap, however most of the time they are less expensive than buying them on-line or from the usual mainstream sellers.
Just a heads up - get 'em while they are still available.