Thanks, Feanor.
Unfortunately, vendor from Hamilton is in a hurry, I might be forced to tell him to go away. He sent me an e-mail saying he has an offer on those Valvo tubes US$140, and I do not like to rush. I am bit older than that... I don't know how to obtain something nice from Tecumseh, where I live, and because of the nature of my job, I cannot compete on e-bay...I'll see what I'm going to do, and when I have enough time, I'll jump on something used. Anyway - more to come, I already have a pair of new, and matched Ei ECC83. I should be able to pick up a matched quad of new Mullards / EH / GL soon, and that is not that much money to invest. Next step is to get something used, but nice and old. After the roll, I'll post the findings, most likely by the mid November. That could very well be the best answer on my own question, since the money invested will not be even half of what I could pay for the NOS matched tubes, packed and protected with the rare Gobi desert goat's beard hair...