Paging through "Weimar Lugers" and "Third Reich Lugers" is unavailing. Costanzo only notes that c/N can be found several different places on a Luger, including the right frame rail. He did -not- document it on the right receiver.
On a partly remembered hunch I pulled out my Simson rework of a DWM First Issue; it has a c/N upright on the right frame by the takedown lever, another position Costanzo does not document.
I'm not sure what this adds to the discussion or means, except that you have quite a mystery here.
--Dwight
|