I have an old sxs that needs some cleaning up(pretty heavy rust). It was given to me by a friend. I have always wanted to put in like a big shadow box with a dead mount
or you could re-furbish it, get some black-powder equivalent shells(I'd use 2 1/2in to make sure the chamber is not too short) and shoot a duck....
all based on a profesional gunsmith wise to old black powder guns, of course....