It's common for a shotgun to have a serial number but no information about the brand name of the weapon. A serial number can be a crucial bit of information in determining the value of a shotgun. From 1940 to 1948 no serial numbers were used on doubles, only capital letters, usually in groups of three or four, the letter(s) sometimes enclosed in a circle, along with an inspector's symbol ( a heart, a diamond, a spade or some such ‘shape', on the bottom of the frame behind the hinge pin.
