Folks, I have more info; I have the gun here in my hand. Serial # 574XXSA, barrel is 4 3/4", says "COLT SINGLE ACTION ARMY .45" on side of barrel. Top of barrel says, "COLT'S PT FA MFG CO HARTFORD CT U.S.A." Pearl grips, looks to be brand new. Even looks like it's barely been turned. Not sure about what generation, but believe it's older than the 20 years I know about. Perhaps the serial # will be a clue? None of the screws look to be buggered in any way. The metal back of the grip looks to have a few slight rust spots; it's been held, at least. No box, no papers; just a magnificent looking gun. Hope this helps.
Mikey