I actually had time to work on this over the long holiday weekend.
I replaced all the pots, which only fixed the scratchy pot issues, but did not fix the record level issue.
I made a guess and figured that the erase head was bad, or not working. Ohming out the record head showed near-proper resistance, so I then moved to the HV generator. There was no output and only one of the driving transistors was hot, so I started troubleshooting. I ohmed out all the resistors, which were *close* to their supposed values. At least they were close enough to work as intended.
I then ohmed out the transformer, which was good, but when I moved backwards to the transistors, I noticed that one was not ohming out correctly, showing open circuit to the transformer.. A close visual investigation found a hairline crack in the solder at the eyelet to the transformer pin..
A quick dab of fresh solder, and the HV was working again.
I plugged the unit in, and gave it a go, and it works great!
So now I need to build a box for the unit and I'll have an EP3 to use in the studio.