I have a Walther PP 7.65, Serial No. 377480 P aC. On the slide and frame it is marked WaA359. It has Bakelite grips and what appears to be the original holster. The barrel and slide have the German Eagle stamp. It is in the same condition it was in when my Dad brought it back from WWII which is excellent. All he told me is that it was a German Officer's gun. My question is - the slide appears to be nickle plated, but it is highly polished. I have not seen any with a highly polished nickle slide and was wondering if you had any insight on why the slide was polished or what could be the significance of polishing the slide?