For your consideration a single vintage 1957 Mullard ECC82/12AU7 tube.Made in Great Britain,Manufacture code 137L D-getter, grey plates.
Test specs 2000/2000.
And a single vintage 1962 Raytheon ECC82/12AU7,JAN military spec,black plates,triple micas.
Test specs 2160/2200



Both tubes are in pristine condition and test as new.All etching is intact and there is no glass discoloration.They are becoming increasingly rare and are priced fairly.
$125 for the pair plus free shipping in CONUS within 24 hours of payment.And I would invite you to check my audiogon feedback under this name.