P-Series Valves, what to do with them?

[ppppenguin]

I think the audio boys love the EL519, the 6.3V version of the PL519. Both are ideal for valve amps without output transformers. EL519 was hardly used in the UK where series heater chains were used in almost all valve era TVs. The E/PL519 is also used in low cost RF linear amps: https://pa0fri.home.xs4all.nl/Lineairs/F...400eng.htm

I assume that both EL519 and PL519 are now getting expensive.