I have a 12 ga O/U w/double trigers and solid rib returned from Germany during WWII. The markings on the barrel include Special - Gewehr - Lauf - Stahl and, after a (3) double ring group, Fried. Krupp.A.G. and under the Krupp name is Essen. The serial number on the bottom of the barrel is #303416. It is in 90% condition. No rust in or out, very good blueing and wood finish. I would like to know as much about this weapon as possible. Can anyone help?