I have a factory 30 round mag that was refinished due to some pitting in spots on one side from the GA humidity.
Rebluing it looked lousy so the finish and all rust was sand blasted clean and the mag has been parkerized and then MolyCoated with a 1 hour bake. You can see where there was pitting on the mag but all rust is long gone.
Sorry for the lousy picture.
$75 shipped insured legal lower 48 states.
Thanks for looking.