The paperwork just means the cab was used for test loke versions at one point. You can see in the video they show the exact GUTS and MAIN from mame so either it was upgraded to that version back in the day and they copy converted it to flash or more likely the hard drive died and they used the mame image to make the flash. I'm not sure where the serial # is derived from, maybe a PIC, maybe the hard drive. Anyway, that is the version in mame. Chances of us finding more versions slim as the hard drives are 22 years old.