Thanks for the nice words, Mechans. I always value your comments about tube rolling highly, as I know you have particularly extensive tube-related experience.
FYI and FWIW the CBS tubes I tried were a quartet of 6SN7GTBs, having red lettering and marked as CBSs, not as CBS Hytrons. Three of them had a date code of 6026, which I presume means the 26th week of 1960. The other had no date code, but said "XG" in the location where the date code was marked on the others. They were in what I believe to be their original boxes. The box containing the XG tube said CBS Hytron, but as I said the tube itself said only CBS. The other three boxes said CBS Electronics. All four boxes referred to Danvers, Massachusetts.
I believe that all four tubes were true NOS, but in any event all of them tested fine on my Hickok 800a tube tester, and were well matched. I tried them about three years ago in my VAC Renaissance 70/70 MkIII amp. I recall that they sounded harsh and thin, compared to the several other vintage tubes I mentioned, as well as in comparison to currently produced Sophia Electrics. It is possible, though, that I didn't give them enough breakin time.
Regarding the comments you provided about 12AX7s, I'll second both the Telefunken recommendation and your words of caution. Also, I can report having excellent results in a different amplifier (a Chinese-made Paxthon push-pull parallel EL34-based amp) several years ago with the currently produced Genalex Gold Lion reissue that you mentioned. I've seen favorable comments here about that tube from others as well.
Thanks again. Best regards,
-- Al