The "Plum" color of the barrel and cylinder has nothing to do with being refinished!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
If you will do a search for Plum you will find more threads than you can even imagine. Not saying the gun has or has not been refinished, but the real reason for the color difference is the steel in the barrel and cylinder have a higher Nickel content that the other parts, and it is the Nickel content that causes the plum or purple coloration as the finish ages. This only applies to guns manufactured during the period when the nitrate bluing process was used. It is very commonly seen with the Magnum revolvers, and frequently with guns that can definitely be documented as having their original finish. It is ALWAYS the barrel and cylinder that take on the plum color as the finish ages! It would not be consistent if the only factor was the gun was refinished!