Hi Lance, Welcome to the forum! The W.W./1387 marking on the rear grip strap is a Naval property marking indicating that this gun was delivered to the Wilhelmshaven Werft (dockyard). This was Imperial Germany's North Sea naval base. To assess value we need to see several clear photos, left side, right side and the serial number under the barrel. If you are reluctant to publish the serial number you can email me at:
normrab@comcast.net. I'll send you the link to the Navy List, which lists all known surviving Navy Lugers. I'd like to add yours to the list. Regards, Norm