(!!!) 6S4A RCA black plate NOS 1960's faded printing (20ma)
(!!) (Best GE Pair) 6S4A GE NOS (23.0ma and 23.6ma)
6S4A GE Admiral NOS 1965 (27.5ma)
6S4A GE NOS 1962 (25ma)
6S4A Raytheon NOS 1961 (20ma)
6S4A RCA USA black plate NOS 1960's (23ma)