Vintage high-end TE is like many mid 90's and earlier vehicles - They were solid designs and builds. So solid that people ran them for decades with minimal maintenance, but now the neglect is showing and overhauls are necessary. You get what you put in, though, and if you take the extra time to inspect and clean everything during the course of your repairs, they'll be set to last for another couple decades.
Agreed... solid, and usually, straightforward designs and builds. I have Tek gear that was calibrated in 1987, put in storage in 1988, and not turned on again until 2019 (you do the arithmetic) and it generally just works. Most of the repair work I've done over the last six months has involved replacing bad caps, cleaning switches, and tweaking calibration.
Granted, I've been working mostly on signal generators, DMMs, and the like that all operate under 100MHz and I've not spent a lot of time working on oscilloscopes, but still... a lot of bang for the buck left in this old gear. (
as I demonstrated when I shorted the plus and minus 150VDC rails through a 2W resistor last week)