Well, it looks to be essentially the same place as this place
http://www.esrcvacuumtubes.com/gridcaps_sockets_productlist.html
I have bought from ESRC several times. Their prices are generally very good and their vintage supplies may very well be sourced from vaccum tubes.net (also a Florida Co). My experience with them has been good but I would like to make known one experience I had with them. Not necessarily bad but worth repeating to possibly save some aggravation.
I had placed an order for an antique G bottle that had been listed at a super good price. It just so happened that the ebay prices for this particular tube were starting to soar. I was told by salesperson that they were having trouble locating this tube. I waited several days after noticing my card had not been charged. I was assured that they had found the tube and my order would sent by end of week. Still nothing and I called back the following Monday and was told the same thing. Still nothing. At this point I knew they would not find the tube - or at least that they wouldn't find the tube at the price they had it listed for because every supplier was either out or sitting on their stock and watching the market prices. I was annoyed and curious that this guy would keep telling me the same line every time I called - and I called him at least two more times over the next two weeks, and like a robot on auto pilot he kept feeding me the same line and promising the tubes would be sent by end of week. My credit card was never charged so there was no rip off. I never got those tubes and never called back. I would still order from them and do from time to time.
I would recommend caution if buying matched pairs of tubes, esp new production . I think these places are great for shopping down hard to find tubes at good prices but for matching I would look elsewhere.
To their credit (I think . . .) ESRC was to my knowledge the last vendor out there who still sold certain NOS tubes at the previously reasonable rates you could find at RES/VT.net. The latter just up and one day decided to list these tubes under a new "special audio tube" section at 3 to 5 X the previous prices!! Blame the audiophool crowd for that one. ESRC may still sell at the old rate - get them while you can.