I take it that the 1842 shotgun is still used occasionally? How much BP do you put in for the charge? How is it to clean, as in wash the barrels to remove the corrosive residue from firing it?
No, alas, the shotgun is not usable. My grandmother thought it was loaded and was afraid it would go off and hurt someone. She hid it in a barn that was used for storage: dirt floor, Arkansas heat and humidity, and time took their toll. My dad and uncle found it after she died. Daddy gave it to me before he died with instructions to eventually pass it on to my son.
My daughter-in-law is the black powder shooter, but hers are modern reproductions.