migueca- I don't know about military/industrial practice, but back in the '60s, it was pretty common for tubes (and free standing tube testing machines that looked like ATMs in size) to be everywhere- drug stores, hardware stores, electronic specialty stores (like Radio Shack and Lafayette) and other places. It wasn't uncommon for a civilian appliance owner to take a set of tubes to such a shop, 'test' them, and buy replacements. (Sometimes, the new tubes were on shelves behind a door at the front of the testing machine).
If it was a big TV/console and the owner was not equipped to do this, there was a business-- the TV/radio repairman, for lack of a better term- who would show up at your house and do the work. People generally weren't fawning over Telefunkens with specific markings; GE was a pretty common brand at least in the NE States and for these purposes, a tube was a tube, there were 'equivalents' that you could look up (still available as pages on the 'Net) and it all seemed pretty matter of fact. By the mid-'60s, I guess, transistor stuff became more commonplace, but the tube regime hung on well into the '70s or later as a fairly common artifact. (I'm not talking about audiophile or specialty applications, just garden variety tube usage, availability and replacement).
