And proper hardening of important areas. (the Stainless Mitchell/Stoeger/Aimco/etc.. ones).
Mauser never made money on the regular models, but ended with a small profit overall with the money they made on their commemorative series.
Mauser's production costs were actually quite good. The problem was that a new pistol cost about 225 - 250 USD and a good surplus Luger could be picked up for 50... Guess what people bought