Hello, everyone hoping to reach out to get some information or get an idea where I can information about this Riffle. I inherited two guns from my grandpa. He obtained both guns post WW2. He got them in a trade for some work on this persons tv that had been oversea's in Germany during the war. One was a 9mm Ruger which so far I have been able to trace everything but the officer it belonged to. Next is the the riffle. It is a Josef Zeller from Dortmund Germany. The barrel is a Krupp. I believe the upper barrel is 16ga and the lower is a 6.3 mm. Just hoping to see if I can get any more info or where to look to get more info. Thank you for the help!