As you know, you're dealing with a very old system compared to its modern descendants. In situations like this, it would be best if someone with the right skills could be closer to the source. Or if that system is accessible by a PC, perhaps someone can get on a screen sharing session with you. Where are you located? Someone might be nearby who can help.
Feel free to contact me off-list and I'll either offer to help or will try to find someone who can work with you. You might have a system that someone recognizes and can navigate easily (from very old memory).
Tony Gravagno
Nebula Research and Development