Many of the "NOS" that are sold are pulls. Be careful who you buy them from. With ARC gear I would probably buy them from ARC. Gold Lion 6922 are great when you get quiet ones. As others have said , Brent Jessee is a trusted source. Tube Museum out of NYC is also. He has a bunch of NOS 6922, not cheap but premium tubes.
I have a whole box of tubes that were "NOS" , and I say were NOS because once I bought a tube tester I found a number of them that were not well balanced or barely strong enough to call NOS.
There are a lot of self proclaimed Tube Dealers out there , be careful.