Gentlemen, this video shows the design is actually quite accurate to WW1 Mauser carbine C96 prototypes.

Some of these might be C96 pistols converted. But they look a hell like the carbine prototypes. If they actually were one of those, those prices might not be extraordinary to a collector. One million made pistols vs 40 prototype carbines.

If made from C96 the stocks look quite spot on.

Interesting some of the prototype carbines did have detachable magazines. Still semi auto. So one if the carbine in the rack has a detachable magazine, who knows?