Perhaps someone should start keeping a database of ordinary Lugers, descriptions, numbers, photos, etc. so that "improved" Lugers and their defrauding owners can be more readily exposed.
It would only take a half dozen or so public exposures to slow the practice to a crawl.

Absolutely correct!
All my little odd bits of WWII paraphernalia that I've picked up over years are growing more valuable every day. I only wish I'd been able to afford to start collecting earlier.