It sounds like a refinished chrome job with no collector value.
Without pictures, it's hard to say, so post pictures.
Many times, war trophy guns were chromed by the soldier who brought it back or by someone later down the line.
Generally, these have no "collector" value, but sometimes on GB, someone just wants the gun for a different reason (as a shooter, as a display, just like it, etc.).
The serial number places it late war, and the grips MAY be the "last ditch" grips, called ersatz grips (if I understand it correctly).
Anyway, because it's chromed, probably not worth that much. Check "sold auctions" on GB and looked for chromed PPs for a good idea of value.
When you say "no roll marks", I assume you mean that it's not marked "Walther". That's a further indication of a refinish since it should have Walther on the slide.
Again, not worth that much.
I have a post-war refinished chrome RZM Walther PPK. I bought it because it's in the right serial number range for a true RZM and I wanted an "on the cheap" RZM, so I bought it. It has no "value" but it was something I wanted in my collection.
I have a better condition post-war chromed RJ PP. Paid a bit more than I should have, but WAY LESS than a non-chromed RJ.
Good luck.
James