I purchased this old Manton muzzleloader as a wall hanger but before I just hang it on wall, I would like to make sure there's nothing special about it. From the markings it appears to be proofed in Birmingham between 1855 and 1868. Does anyone know what the "10" on one barrel and "11" on the other barrel means? The only other markings are "Manton" on the side plates and "London Fine Twist" on the top side between the barrels. I seen the hammers do not match. I suppose this is from one getting damaged and replaced at some point. Any more information anyone can provide is greatly appreciated. Thank you.