Hi Steve,
Back to your question about stock lugs on P-08's...one of the going theories is that DWM/Mauser/Krieghoff continued to forge and mill the stock lug so they would have a easy and firm way to hold the frame/gun for final finishing and polishing steps in the manufacturing process.
On first blush...this seems logical and reasonable...but that is a lot of extra milling/machinging to finish the stock lug just to gain a way to hold the frame in a jig for other work...I am not convinced this is the answer...but this is just a WAG on my part...
But the Swiss folks at Bern decided not to build their Swiss lugers with a stock lug and figured out another way to hold a frame firmly during finishing and polishing steps...not sure why the Germans did not come to the same conclusion...
Regards,
Pete...