(!!!!) (Single) 6BK7B RCA NOS "U" getter 1950's (7.5/8.5ma)
(!!!!) (Best Pair) 6BQ7A RCA black plates NOS 1967 same date codes (15/14.5ma and 13.5/16.5ma)
(!!!) (Best Single) 6BQ7A RCA black plates NOS 1967 (11.5/13.5ma)