Hi there.  I am wondering if anyone can help me date the manufacture of my walther ppk.  I have been digging hard on the web and have turned up empty as well.  I called Walther USA and they couldnt even tell me.  I have helped friends find born on dates for other guns, but not this time.  On the right side behind the trigger, the 6 number serial starts with   331 and ends with a k.   Also on the eject port is a stamped eagle or set of antlers with an "n" underneath.  .The left side of the slide says  "Waffenfabrik Walther Zella-Mehlis (Thur)      Mod PPK".   It is also gun black with brownish handles. and has a lanyard right behind the clip.  Just interested if anyone know anything about it.