That is a very nice find. Congrats. I have a 4 screw that I bought a few years ago that I love.
A 1959 gun in good shape. Those are getting hard to find.
I had Highway Patrolman pre 28 that I think was built in 59 that had the same issue but you could only see it in certain light. I left it like it was and did not try to correct it. It is to me one of the characteristics of the model. I am not sure they all have this issue but I understand it...
Several years ago I bought a used 4-screw Model 19 which came with beautiful diamond target stocks that were not numbered. I have no letter but always assumed they were original to the gun.
Allan is correct. Along with changing the cylinder, a new barrel was installed. This one being previously a 25-2 it was a 45acp in it's previous life and came with a 6 1/2" barrel. He also brings up something I did not know relating to the different heat treatment that a 25 or 29 would...