Walther MP-PP at James Julia
 

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! :D

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...