Most of the Stevens, Savage, Springfield dbl. bbl. look a lot alike, but some have the 2 pins on lower side, rear, of the breech situated different. On most, the pin closer to the rear is lower than the pin more forward. Both mine, A Springfield 20 ga. ser. # E12625 and my neighbors Springfield - J. Stevens Arms 12 ga. ser. # E34630 have the rear pin higher than the more forward pin. Wondering if this may narrow down the mod. number. Also on mine the screw holding the top snap (unbreaching lever) on is installed from the top, on my neighbors this screw is installed from the bottom. From what I've found both having a capital letter with the ser. # means they were both made between 1913 & 1939. Sorry, I know little about computers, & know nothing about putting pictures on them... Anything more than I know now greatly appreciated.