Some years back I bought two Remington 12 guage riot guns. They were covered in rust. Held out hope that I could safely remove all the rust. 1st one I paid $195 and the second one a hair over $200. Started out with gun #1, complete disassembly of all parts. 4000 steel wool and some CLP. Took the shotgun barrel and liberally coated it with CLP and let it soak while I ate dinner. Then used the 4000 steel wool to remove the rust. Slow circular motions with frequent stops to remove the rust with paper towels.at the end of about two hours all the rust on the barrel was gone Light coat of clp on the barrel. all the rust on the action bars,and mag tube was removed the same way. No pitting on any of the steel parts was a removed the same way. After 4 hours when I finished I had a Rem 870 in almost perfect condition. Sometime later I made it to a local range and test fired it. No failures to fire or to eject.2nd shotgun when cleaned up as the first when done also had no pits. Except the barrel extension had a large burr from not making sure the mag cap was screwed on tight when firing the gun. Jerry Knuhausen to the rescue.Removed the burr with small stones and sanded with very fine grit (600) to polish where the burr was and cleanup the damage where the burr had been slamming into the extension cutout in the receiver cutout itself. Range tested no failures of any kind. Could easily flip both shotguns for about $100-150 over what I had paid for them. Sanded and refinished one so when done I had a nice Remington 870i riot gun with 20" barrel. The other 870 had a 21" barrel.
Maybe not the same as rescuing the browning, but shows what can be done with a minimum of tools, and some cleanup supplies. Frank