John Ulrick of Spectron Audio passed away a few years ago. I don’t know if his widow is still alive to inquire about spec design sheets. She ran the front office unit of the business. I think an business partner took over and shuttered the operation.
Deltronics (on N. Halsted St. in Chicago) has a solid reputation. They don’t always need an electronic spec if they can identify and replace defective parts. Caps (or FETs) are likely culprits to go out in these designs.
They just recapped one of my ExactPower conditioners last week without needing a spec. And that particular item was one that they needed a spec for to resurrect a second, completely dead, ExactPower conditioner I bought from a high-end dealer on EBay for parts about 5 years ago. Luckily, I had that spec sheet from the original design team.