Bad capacitors is old news.
I was trained as an electronics tech by the U.S. military in 1953.
Vacuum tubes and paper caps were the order of the day then and you could usually spot a bad cap visually because the oil in the electrolyte drained down and soaked the cardboard. They always seemed to be soldered to the board with a teaspoon of solder?
We're a long ways down the road now and caps are prettier at least, but I have no idea if the failure rate has improved in relation to the time?http://www.antiqueradio.org/recap.htm