WTB: Variants of 300B tubes and specific 300B and other vacuum tubes.

AD100: Singles or Pairs (preferred) by AVVT (Vaic)
32B SL: Singles by AVVT
320B SL: Singles by AVVT

As to actual 300B tubes, please let me know if you have any of these:
-- Svetlana Electronic Devices (SED), JJ Electronic: Singles only
-- Elrog ER 300B (non-metal, black bottoms): Pairs preferred

NOTE: Also looking for certain tubes -- singles or pairs...
*** ECC230 Philips

I look forward to hearing about what you've got -- new/unused, NOS, low hours, or gently used. Please send PM with details. TIA!