Just got back tonight from my travels this week. Now to play with the 1130 and related toys again.
PERTEC D3422 DRIVE RESTORATION
A fellow enthusiast who has past experience restoring and working with this disk drive has shared some materials and tips with me! I am just digesting what I found right now, after which I will likely have a few more questions. All that must wait until I have the power supply repaired.
For the power supply issue I am debugging, as far as I can see from the schematic there is just one path for the +20V raw power to get down to the circuitry for the -20V raw input, where parts are committing suicide. Everything else is separated by ground in the middle. Thus, unless some failed component has created a sneak path down to the op amp and transistors that are frying themselves, it can only be a small number of parts causing the problem.
The transistor replacements arrived today and I soldered the part in to replace the burned out Q30 in the power supply. I put a replacement op amp into the socket I had installed, to allow quicker replacement until I nail the core problem.