How old is this gun? Cartridge or M/L ? I guess 32 ga would be about a .410.
If it has no collector value, you can draw file the metal back to bare metal, sand it and cold blue it.
I build M/Ls and rust brown some barrels, cold blue others, it is really easy to do. A rust browned barrel with a few pits looks takes on a nice antique look, the best part is it will never rust again as the finish is hard as a rock.
Here is a rust browned lock, done with Laurel Mountain Forge browning solution.