I have a blued Kimber Custom TLE II. It would rust in the vacuum of space coated in whale fat. I decided to go ahead and try aerosol Gun Kote in satin silver. It’s a ceramic bake on coating.
I completely disassembled the gun, sand blasted, sprayed it all with brake cleaner, heated to 100f, sprayed the Gun Kote, and finally bake at 350f for 30 minutes.
I feel like it has a pewter patina look to it.