Hi,
I think I found a similar crt made by motorola in 1981 but unlike mine it is a twelve inch crt but it has similar schematics and pin labling as mine so here it is:
https://drive.google.com/file/d/0B5vW-k7HbsL4TUFYQlVMOGZOOWs/view?usp=drivesdk
Look at page 14 (and pin 17 too) of the PDF and there's a pinout for the edge connector. It looks like it more or less matches up, but the pin numbering you're using is backwards (you said +12V was on pin 4, Motorola put it on pin 7).
The high negative voltages are for the "remote brightness" pot -- which makes sense. You put a 100K pot on those three terminals so the user can control the brightness from the front panel.
Apply +12V and ground to power the thing up...
Now you've got three signals left --
- Horizontal drive (HSync) -- page 17 says this is TTL
- Vertical drive (VSync) -- page 17 says this is TTL
- Video -- this is probably analog, but the monitor may take TTL too
Chances are, you can probably run this thing from an NTSC or PAL output, if you hooked up a sync separator (LM1881 followed by something to split the composite sync into H and V).