Help Please? 1931 Walther PPK .32 NO MARKINGS

Greetings from WI! I just picked up this Walther PPK everything is all original and has not been altered in any way. However, aside from the serial number behind the trigger and the last 3 digits scratched into the inside of the slide. No logo Roll markings no proof stamps either on the slide or the barrel breech. I have heard of no marking models made towards the end of the war but what would be the point of having no markings on such an early Specimen? Anyone have any information? The dimensions are all correct Everything functions exactly as it should. THIS IS NOT A FAKE, NOT A FRANKENSTEIN, EVERYTHING is correct down to the hundredth of an inch. Any ideas? I have many pre war PPK Pistols, this on has me and Walther stumped. Yes I called Walther. They are confused and interested as well. If they could only talk. I would love to hear the story behind this one. Thank you in advance dir for any help!