NRA Museums director Jim Supica looks ready for a street fight. He shows John Popp three combination pocket protectors - small firearms carried concealed that had a backup means of defense. James Reid's "My Friend" knuckle duster pepperbox revolver can also be used as a brass knuckle. "Les Apaches" knuckle duster pinfire revolvers in five and seven millimeter were named for the Parisian street gang that used them. They have full brass knuckles as well as a folding blade. They seemed like a good idea at the time.