When I was a kid, my father would take things to the shoe-repair shop, for ex., or to the electronics-repair shop.
I can remember when the TV went on the fritz, my dad would pull out all the vacuum tubes and take them to a convenience store like 7-11 or Circle K. There was a machine there with all the different sockets to match the tubes and you plugged each one in until it told you one was bad. Then you got a replacement from a cabinet underneath the machine.
They also sold a kit of paired stickers so you could put a sticker on the tube and a sticker on the socket when you pulled it out so you'd know how to put your TV back together.
