You know that the only way to really tell a refinish is to have the gun in hand. Pictures are never good enough to be 100% sure either way. I notice that the wear patterns look like they have taken a long time to appear, plus those conditions you have mentioned, help tip the scale towards original, at least for me. I can compare that gun to a 38 Single Action, 3rd Model (Model 1891) I own from the same era and am certain it is original. Color of bluing is the same except mine has more patina showing through the bluing than the OPs.