Now this is a handsome pistol! I have always admired the Walther PP
(but not the PPK) and seeing this PP-on-steroids is really delightful!
Forgotten Weapons linked the auction lot.
http://jamesdjulia.com/item/2235-373/
Cut for a Luger stock attachment...
I do question the caliber of this prototype - 9 x 23 is pretty strong for a blowback handgun...
One other Walther prototype I liked was the HP with the slide-enclosed hammer...