Earlier I mentioned that my father and I went together in 1958 to purchase a 1939 Luger. It has a mismatched toggle train. The muzzle had apparently been damaged as it was countersunk about 3/16 of an inch and braze was used to fill a gash of some kind. I still have the barrel.
It wasn't reliable at all so my father ordered an Italian made 8 inch barrel and had it installed. It was very accurate but still not reliable. Years later I would finally realize the problem and radius the chamber mouth. It now works flawlessly.
I shot it just last Friday. At a measured 24 yards on 8 inch steel plates, I shot two magazines without a single miss using my reloads. 115 grain Berry plated bullets, 5.6 grains of Hodgdon CFE Pistol powder and an OAL of 1.155".
The composite picture below shows the Mauser in B&W as it was when we bought it 63 years ago. The color picture was taken not long ago.