Just turned 73 today and my old brain gets kinda fuzzy at times, but if I remember correctly, the DWM "alphabet commercial" Lugers were made from war time Lugers, and the date was removed from the top of the reciever by DWM. If you look at one of them from the muzzle, you can see where the top of the receiver is thinner than on a dated Luger. I haven't measured one, and the receiver still stands proud of the bbl flange, but it definitely has a "flatter" contour than the dated guns.
So, couldn't you compare the measurements of an alphabet commercial to a dated Luger to determine how much metal has to be removed to remove the date?
