Wondering on value of this gun, has been in the family for decades and has been to the range a few times but spends most of it's time under a mattress in a childless house. I have taken pictures however don't know how to attach in the required format. It has matching serial numbers in various spots and the German symbol with WBA140...I figured out how to get the pics! How does one go about selling an item like this? I have too many guns and would rather sell than have them get stolen one day. Thanks for your time!