Two words: Brent Jessee.
well, that was four, so, I have bought several pairs of 1940’s-era drivers (6SL7, 6SN7) and for the price, matching, insurance (optional) I couldn’t be happier.
never called, just emailed. I figure he must be busy and I knew what I was looking for.
most eBay “closely matched pairs” seem matched by size/shape or model, specs on testers with10-20% tolerances when new/calibrated and the prices these days? Fugeddaboudit.