I had a chance to connect with my mechanic regarding the status of the 1990 Audi V8 Quattro I picked up a few weeks ago. Seems like mostly good news, after the big job of replacing the deadly-if-left-ignored timing belt was completed.
The brakes, which are the notorious "UFOs" with their novel floating caliper design, were a big concern. These were finicky when new, to the point Audi replaced many sets with standard rotors and calipers. With the brake fluid proactively flushed, the car stops smoothly with none of the chattering this unusual design was known for. That's a huge credit to the previous owners who obviously paid attention to the small stuff. The transmission fluid was also proactively changed, as the auto 'boxes from this era were known to suffer without regular fluid changes.
The window switches were not responsive on the front windows when the car arrived (well, the driver's side worked once and never again.) These were replaced and the windows now work without issue. That's the cheapest outcome you can hope for.
I'm hoping to bring the Audi home next week. The only other major outstanding issues before I either sell it or start to drive it regularly are replacing the engine mounts which have not perished but are getting there, and converting the (still functional) R12 A/C to R134.
Driving impressions to follow...