If you take your photos over to the P38forum.com, which is our sister forum, they also have a section for the walther pocket pistols and the experts there can guide you with more accuracy.
I don't know much more than you when it comes to these pistols, except that I like them a lot. But I don't believe that this pistol was made as early as has been described. I THINK this may be a post war PPK, but then I am telling you more than I know...
If I had the money, and it was appropriately priced, I would buy this one to carry!