The original US made tubes can still be found on Ebay or Reverb, but they go for an arm, a leg, and a left nut. 12AX7, 12AT7, 6L6GC, 6V6, EL34, KT66 tubes are still out there, collecting dust in some people's basements or attics, but they've become scarce with the advent of Ebay.
I was always more of a Fender Stratocaster, Fender Twin Reverb, or Marshal JCM800 kinda guy, until I gave up playing altogether back in 2005. I was getting too old, too crazy, and the music scene in Texas was changing too fast. Plus the fact that everyone wanted to be a businessman and not an artist.
I have a brother in Illinois who has been collecting vintage gear ever since the late 70's, as well as making his own guitars. He became a born-again Christian and only plays for himself and his wife these days.