Could this be a Krieghoff rework of a DWM luger that got "sanitized" of any HK proofs on the right side and on the rear frame HK markings...?
When I saw the initial photo of the rear frame area, it looked to me like heavy sanding occurred there...
Simpsons LTD has this one for sale :
http://www.simpsonltd.com/LugerRoom/.../K-03/K-03.htm