We've all heard about "collector" guns, and shooters - but this is a "survivor"...
So, it's clear that parts have been replaced on this gun, basically because of the different appearance of things like the grips (right either smooth or worn smooth - left is a diamond profile checkered grip) and bluing loss (cylinder and ejector rod look quite different than the rest of the gun).
As a parts gun, considering the keen eye of the evaluations above, I'd put the revolver's date of manufacture as "all of the above"...
From the hole under the cylinder release button, it's probably had one of the action pins replaced as well (hammer pivot?)... The work looks well done - perhaps as you'd treat an old friend that needed some maintenance.
Note that the defaced serial number on the frame (the legal one) could be an ATF issue.