Recently acquired a Parker Bros dbl hammer shotgun. From serial number it was made in 1885. The action and stock are in fair condition. The barrel is a different story. It is the twist steel that had a brown patina finish with plenty of heavy rust. I'd like to clean this up. I used some steel wool , .0000 removed the light stuff but I still have a lot of pitting. To remove the pitting I'm going to have to remove the brown finish. So where do I go from here. Remove the rust and pits, and brown patina, then re-brown? Leave it unfinished? Or just oil it and leave the pitting. Not that I have any desire to sell this, but I would like to maintain the highest integrity possible.