I believe most vintage receivers suffer most from bad transistors than out of spec caps. There are certain small signal transistors that are known for failures.
.
that's a very good point, and every time I've seen a parts list after our receivers been restored, there's always transistors in the mix.
I just made a remark on another thread, but I have a pair of Classe Audio M700 monoblock amps that are approximately 30 years old. They blew fuses back to back and I was worried that they needed to be recapped. These were sent back to the factory repair place in Syracuse NY. To my amazement between the two amplifiers there was three capacitors that needed to be replaced, and they were in the standby section only, nothing in the audio path. The tech that worked on it remarked how good the capacitors are that they used, even back then. The wrong type of fuses were recommended to me, and even though the amps were on their own separate dedicated 20 amp line they just had the wrong fuses in them. So there is a definite difference in premium capacitors, and other capacitors.