Hi Bill,
There are some interesting points in here. I especially like trying to make a connection to Krieghoff, though I agree there will never be a way to positively confirm or refute such a connection.
But concerning the C/N proofs being on the left of the Dreyse rather than the right, I'm afraid that is a slender reed upon which to place much reliance. On a Luger, it would have been tough to find a place on the left side to more or less line up the proof marks (the sear bar and sear get in the way). Also, the placement of the C/N proofs on the right side of a pistol was not unusual - I'll attach a copy of a shot of an Ortgies to illustrate this.
Best regards,
Kyrie
http://boards.rennlist.com/upload/Ortgies_R_Photo.jpg