[Ron Wood]

Wes,
I respect and value your opinion and disagreement. I consider you to be a very knowledgable individual and normally I would bow to your judgement. But not this time. I disagree with the notion that "Such process would be totally impracticable, cost prohibitive, and the refuse rate would be astronomical". I believe that the manufacturing practices existing during the production of Lugers, from the earliest date, were fully capable of routinely attaining the tolerances required to accommodate such an assembly process.
With sincere regards and genuine respect,
Ron

An afterthought: "Any production technique as illogical as the assembly, marking, disassembly, and reassembly would have to be documented to be believed. It is too fantastical." In the sequence I suggested, the index marks are applied prior to assembly, then partial assembly is performed to gauge tolerences, then disassembly for headspacing and extractor cut, then final assembly. This isn't a terribly complex operation and could be accomplished quickly, expecially since all of it is performed before final torque and disassembly is quite easy.