I have some tubes made for the navy to be used in a gyroscope. I think the brand name was Sperry ( name of the person who invented this design). I cannot imagine that they will send a submarine away for a long journey with a gyroscope containing tubes that would not be perfect.
Of course a durable tube with the right specs does not automatically give you a good sounding tube.
But i do know that rectifier tubes made for the army many decades ago can be used for more than 10 years without any problem. Of course i use them with choke inpt which gives them a much easier life.