Can anyone give me date the age of our Walther model 9. This all of the information I have. Walther Model 9 “Vest Pocket” Pistol, Sn: 852567, Manufacturer : Waffen Fabrik Walther Zells Mehlls, 25 Cal. it belongs to my wife and use to belong to her father. She is thinking of selling, but wants to know its age so we can get an estimate of its market value.