(!!) 412A Western Electric NOS 1969 (51/40 and 52/40)
(!!) 412A Western Electric NOS 1970 (53/40 and 53/40)
(!!) 5R4GB GE NOS 1983 (54/40 and 56/40)
(!!) 5R4GYA GE brown base NOS 1972 (52/40 and 54/40)
(!!) 5R4GYA GE Hewlett Packard brown base "D" getter halo NOS 1959 (51/40 and 52/40)
(!!) 5R4GYB RCA like new 1963 a few oxide filament flakes inside tube slightly tilted glass (50/40 and 52/40)
(!!) 5R4GYB RCA rebranded Raytheon NOS 1960's (50/40 and 53/40)
(!!) 5R4GYB RCA used/very good 1961 (48/40 and 51/40)
(!!) 5U4GB RCA NOS 1970 some white oxide flakes inside tube (55/40 and 55/40)
(!!) 5U4GB RCA used/good "D" getter 1960 a few scratches on base (53/40 and 57/40)
(!!) 5V4G RCA NOS black plates 1955 (60/40 and 60/40)
(!!) 5V4GA RCA branded GE gray plates used/good 1967 (57/40 and 57/40)
(!!) 5V4GA RCA NOS gray plates 1971 slightly tilted glass (60/40 and 60/40)
(!!) 5V4GA Sylvania branded Dumont NOS 1960's (57/40 and 57/40)
(!!) 5V4GA Sylvania NOS 1957 (56/40 and 56/40)
(!!) 5Z3G National Union burgundy base NOS "D" getter 1951 (56/40 and 59/40)
(!!) 5Z3G National Union NOS "D" getter 1940's (52/40 and 54/40)
(!!) 5Z3G Sylvania Italy NOS 1960's (54/40 and 55/40)
(!!) 5Z3G Westinghouse NOS 1957 (59/40 and 61/40)
(!!) 6AU4GTA RCA used/good 1960's (89/60)
