Tubes

Avoid eBay. 50/50 and not worth the risk to the gear. I have bought lots of vintage tubes from several sources. Those listed above are all top notch. Add Grant Fidelity - sells the spin-off brand from psvane - should be trusted. For eBay, I’ve had luck with all the rectifiers I’ve purchased but not so for input tubes or power tubes. 

I just bought from Upscale a matched pair of Gold Brand Sylvania vintage 6SN7 (GB-6SL7WGT) for about $100 apiece for my Cary phonostage.  They are excellent, especially very quiet for the phonostage.  I’m not sure that Upscale has more of these, perhaps they could be found elsewhere.

http://tubedepot.com/ TubeDepot is another good source for tubes. 

+1 @tvad!
I wouldnt trust ebay for such a purchase.....
I have used Brent Jessee, as well....pleasant to deal with, great advice and selection...in this case I believe you get what you pay for, with diminishing returns.....
Good luck

I bought several tubes from ebay, including a rare nos sylvania 5751 disc getter and a nos rca 7025 gray plate, both of which are installed and sound great. You pay your money and take your chances....it helps to look at the sellers feedback. These sellers both had thousands of 100% feedbacks. These tubes were installed into a Tavish Design classic phono preamp. The third tube, a 12au7, is a GE JAN military tube purchased from Kevin at Upscale Audio. This particular 12au7 is one of the quietest available, adding excellent detail, low noise and a blacker back ground.