I picked up a Systron Donner model 7004 about 10 years ago, dating from about 1970. I was going to scrap it for the nixies before I realized it was still as accurate as my best modern DVM and had one more digit. But it wasn't NASA - I think the calibration sticker (now lost) said Goodyear. It had the optional battery pack. Inside the case were two 6V lead acid batteries driving a board that delivered 12V AC to a separate winding on the main transformer. I have the manual, but it doesn't say what the nixies are - just "Tube, readout, V0132". The next item is "Socket, readout tube, X0179" so I know they aren't wire ended.
(poor photo - low light)