My father bought this 42 byf (and a free box of ammo) in 1948 from a Missouri gun dealer for 35 dollars. I still have the original telegram communications between the dealer and my father. I'm thinking he wanted a Luger when he was over in France during WWII but was unable to get one. He did get a 1934 model Beretta in .380 while in Italy just before the invasion of the south of France. I'm sure he had it with him as he stormed the beaches. And then, while in France, he picked up a WWI vintage Spanish Izarra (the rarer long barrel model) that was made for the French military. While in France, he made some clear sweetheart grips for the Izarra and I'm thinking that's what inspired the multi color grips he made for the Luger. I do have the original Luger grips, though.
The Luger is all numbers matching except for the mag which is period correct. I got the mag from Mike Krause in exchange for the one in my father's gun which was apparently for a much earlier Luger. The barrel is a little rough but grooves and lands are good and it's very accurate. As you can see, it's been polished a bit and reblued. A good shooter.