Mauser grip frames are numbered, from beginning to the end. But on 1930 and Schnellfeuer, it's numbered inside.... so it creates a weird situation -- supposedly, according to the rule, the number on the grip frame should be recorded in the "bound book". However,,,, I don't know how many people record that partial s/n on 1930
On mismatched 1930, I bet most people would still record the full s/n on the barrel.
For those .45ACP, most of them are assembled in 1980s. Not sure why people paying big bucks on them....Probably most of .45 were advertised as "only 8000 made, most destroyed" etc. If everyone says so, it must be so. But, if viewers track it a little bit -- they probably would find this "super rare variation" appears almost every week on gunbroker.com. Back a few years ago, it's available at a few hundred dollars.