Tubes?

There are 2 options.
1. Use a tester, but some only give you a good-bad decision, no idea of how good. Its been a long time since they've been at the five and dime (a long time since there has even been a five and dime), but you may find one at your local independent hi-fi or tv repairman, or if you post your location, someone here may volunteer.
2. Sub them in to a component that uses the same tube type, but again, that will only give you a go-no go decision

I would either send them and pay a small fee to a reliable Tube supplier..or Ask someone on this Audiogon site that has knowledge and owns a calibrated tube tester to test them for you.....Other than that its not worth taking a chance unless your willng to take that risk?

It's also possible the tubes you've found are not worth the trouble even if they test perfect. Of the thousands built, only a double handful remain popular in high end audio.

If you list what you have, I and a dozen others here at Audiogon can tell you if they are desirable. If they are desirable it's worth testing them and putting up for sale or keep for yourself.

I'd stick to Albert's advice. It is sound, I think. Give us a list of what you have, wait for responses and go on from there.