Yup. What's needed is Investarms trade rifle sidelock. It's needed because of the trade rifle barrel being used. I'll trade straight up with the more attractive sidelock pictured. The assembly being offered was repaired and inspected by a experienced gunsmith a month ago. Aside from being more plane the trade rifle lock is contoured to accommodate the nipple pan, (not sure of correct name here), on the trade rifle barrel. I'd be willing to buy a trade rifle lock if a trade wasn't in the offering. Pictures presented. Ask questions, if I can't answer I'll make something up. (Kidding) Steve