yeah, if you go to Watford Valves, they'll have info on the Harmas
I don't think Watford makes any of their own valves - kinda like Groove Tubes used to be - but they have very stringent testing & matching
I got some Mazda 6V6s from them, but unless you get enough of an order, the shipping is a deal killer.
I think the JJs are probably still the best current production EL84. Some of the Harmas are Russian made, to certain specs.