Hello,
I did some searches on the web, and I found a few threads in previous info.labview archives (around 1998, I think) that mentioned customers using a LabVIEW driver for this device. I'm assuming they obtained the driver from the manufacturer (EG&G). I recommend you contact them. If not, search the web for "EG&G 273A labview" and you should find some discussion threads in the info.labview archive...if nothing else, you could simply contact the people in those threads and ask them if they still have the drivers.
Good luck, and have a good day.
Sincerely,
Darren Nattinger
Applications Engineer
National Instruments