I have to partially agree with the original statement. Think of a stereo receiver as a rotting basket of fruit. Once that fruit has finished rotting, you have to cut out all the ortten parts and in many cases it's just not worth it.
In 1967 our family bought a 140w sherwood 7800 AM/FM receiver. By 1984-5 it was not working properly. Turns out the selector switch had rusted. But, it failed in a way (Only the FM section wasn't working) that appeared like it was an electronics issue. I am kind of a klutz (despite graduating the previous year with an EECS degree from MIT), and screwed it up a lot before I figured out the actual problem.
If you have ever worked on a British-Leyland car (triumph, mg, mini cooper), you will understand. If you don't drive those cars for 30d, everything stops working, all the electrics are brass and they corrode and stop working. The car must be driven or else it fails - totally, and i mean everything, no ignition, no headlights, no nothing!
With many stereo receivers this can happen too. Although nearly 100% of components can be replaced with modern components, i think a lot of people buy these items for the challenge and because they are handy enough to swap the components themselves and they enjoy having the look of vintage items in their house. The more modern (1982+) stereo receivers had excessive feedback amplifiers to get the specs down to 0.08% or 0.05% THD. That really screws up the sound in some way that many people can't quite explain. So they buy an older receiver with the 0.25%, 0.5%, or 1% THD (our state-of-the-art FET Sherwood 7800 is an example of a great receiver with 1% THD). Having said this, I just bought a vintage 1990's cassette deck, a Yamaha KX-W952, and it just arrive at my house 30m ago ...
By the way, our Sherwood S-7800 cost $349 in 1967. I am amused that today you can have one for the low-low price of $255-$299. Not worth it, imho. Once you experience a "do not repair" stereo component, you are through, for life ...
