Thanks for posting pictures of your Grandfather's revolver! I have enjoyed seeing it and the discussion and information. I have learned something about the 1902 that I have (also an early model with a 4" barrel). I'm quite sure mine has original finish, but not much of that. I think it shows what another member mentioned as the fragile finish that tends to look like it flaked or peeled off. This is SN 28,069.
Rob