(!!) (Best Overall Pair) 5V3=5AU4 GE branded RCA NOS 1960 era (56-56/40 and 54-58/40)
(!!) (Recommended Pair) 5V3=5AU4 Sylvania NOS 1960's (54-54/40 and 54-56/40)
5AU4=5V3 GE FAT BASE large black plates NOS 1958 (52/40 and 54/40)
5V3 GE branded ITT NOS 1960's (52/40 and 54/40)
5V3 Raytheon branded RAD-TEL NOS 1961 (53/40 and 54/40)