386XL with "Cylinder burn "

[Shooter6br]

Looked at used 386XL with Millet red dot.It had no orginal rear sight.What bugged me was it had a discoloration at the rear of the cylinder.The cylinder is stainless steel with some sort of black finish. I never saw that on any blued cylinder look like that.What is up with that? I passed on it.

[Shooter6br]

I was told these guns have a "clear " coat.Solvent can remove it.Shame such a nice pistol has a delicate finish.