Is there a site that can tell me how old my Model 11 is using the serial #? My serial # is 81301 and its a 12ga. I'm hoping I can tell what buttstock I need by its age. My buttstock is broken and very hard to get a accurate reading on. I know the metal tang on top is 3.5" and the bottom is 3-1/8", but I can't measure the wood tang slots, since its broken.