Though they don't have a huge value now they may someday and I'd refrain from chopping anything. I don't recall if they have the removable barrel or not, but if so I'd find another barrel first myself. It is after all a Browning design, and you don't really see may of them around anymore.
If the gun is in good shape overall, I'd just send it out for a re-blue, clean up the stock and leave it at that. There's plenty of cheap shotties out there that will fill your 20" barrel needs for < $200. Worst case if there's some choke damage/muzzle damage,,,put a Cutts Compensator on it and keep it period. You see those around at shows occasionally cheap and they really work well, I wish they would manufacture them again, there old fashion but really sweat.
I had an old hump back police Browning that had one and with a 18" barrel and a ex full choke tube I was knocking down ducks and geese at 75-100 yards with it. What a handy blind gun that old girl was, compact but effective at range with the right choke/ shot combo.