In the UK we had small electrical stores where you could buy valves (as we called tubes), or you could get the shop to replace them, then along came cheap transistor radios and a lot of the magic vanished! When I was about 14 I was given an old 1930s valve radio by my neighbour, nothing could pull in the shortwave stations like it could, took half an hour to warm up though. A few years later when I was at University, valves weren't even mentioned in lectures, not much on the Germanium transistors either which I'd played about with as a teenager - as they were cheaper to buy than Silicon ones.
EVERY drug store had a tube tester and a stock of tubes under it. When you think back it's kind of hard to believe, as it doesn't seem that the average consumer would be pulling tubes and replacing them, but as I recall, they were pretty easy to spot when bad. They just didn't light up!!
My brain has scattered remembrances of things like screen grids and suppressor grid spacing, and I somehow remember that my table top radio once needed a 50C5 tube(!!). Why I remember that I have no idea.
Very good flashback Jim.