(!!!) (#1 19J6 Pair) 19J6 RCA "U" getter halo NOS 1952 same date codes
(!!!) (#2 19J6 Pair) 9J6 RCA NOS 1950's - 1960's same internal plate structure, different getter halo shape
(!!) (SINGLE) 307A=VT-225 Sylvania NOS 1940's (44ma)
19J6 RCA NOS 1960's
19J6 RCA Victor NOS 1949
307A=VT-225 Ken Rad NOS/75% coated glass 1940's (34ma)