I found "Krebs" means "Cancer".(the crab in Astrology)
According to levine and Goins, Peter Krebs used a lobster stamp....yours looks more like a crab, to me. Maybe those writers couldn't tell the difference
I would be inclined to do further searches using "Kronenkrebs".
I am interested enough to do some more, myself
As an aside, several of the discussions on German forums referred to the "cancer" stamp on Kronenkrebs knives...but the translations were poor and confusing.
A message to denialists, everywhere:
IT BLOODY WELL IS!