I just picked this revolver, and I would love to put a red dot on it. I have searched and searched, and I haven't been able to find any mounts that will mount right on, I've seen the Weigand mounts, but those seem to only be for the 6" and 8" models. I'm sure someone has mounted an optic on a 4" before!
I know there is photo of that exact thing in this Revolver forum but I can't get this stupid "Search" function to work. You might want to call Weigand and see if they still make a mount for the 4 inch Tracker (is yours a Tracker or the M44?).