84=6Z4 Belmont engraved base used/good 1930's (50/40 and 50/40)
84=6Z4 Greylock USA by National Union like new condition 1940's (49/40 and 54/40)
84=6Z4 Philco used/fair 1940's (42/40 and 43/40)
84=6Z4 RCA NOS GT-shape glass slightly tilted glass 1967 (44/40 and 47/40)
84=6Z4 RCA NOS GT-shape glass tilted glass 1967 (47/40 and 48/40)
