(!!!!!) (Best Value) 5U4G RCA used/tests like new "D" getter 1955 guide pin reglued on base (57/40 and 61/40)
(!!!!) (Best Single) 5U4G RCA used/tests like new "D" getter 1955 (56/40 and 56/40) 1% section balance
(!!!) (Good Single) 274B Western Electric printed base NOS 1959 reboxed (53/40 and 60/40)
5U4G Crosley Sylvania used/good 1950 (55/40 and 56/40) stains at top from usage
5U4G RCA used/good 1953 a few oxide flakes inside tube (50/40 and 52/40)
5Z3P Chinese (substitute is 5U4G or 5U4GB)