NOS US made 6BW4 tube. These can interchange with 6V4/EZ80 by installing a jumper on the socket (see basing diagrams).
6BW4 USA NOS Tube
6bw4
$5.95
Triode, USA
Customer Service
M-F 9AM-4PM CT 1-800-774-3201
Email us Anytime: questions@triodestore.com