It does bring back memories for me also.
My dad had many cases of tubes up in the attic. (don't remember why?)
He bought a tube tester from Radio Shack. It looked like a small suitcase.
So, whenever the TV picture got a little wavy, I'd pull out the tubes one by one, and test them.
Then, I'd go up into the freezing cold attic with a flashlight and look through countless cases, until I found the right tube.