The lore of patina....... JFC..... aged and hardened rust and grime.......
Whoever started the attached valuation of " patina" however many decades or hundreds of yrs ago in relation to firearms.
Needs a swift kick in the nuts from someone with a time machine.
Your lucky day ! Just happens I have a once used time machine with a touch of patina on the door handle . Works great ! What’s it worth to you ? Kenneth