Most of these 5" sets were built by Gold Star, Orion or Samsung.
If the set has a FCC number go to FCC.gov & look it up. Will tell
you the OEM & OEM model number.
Early in line jugs except Sony used the dots or rectangles. RCA
built most of them in 13, 15, 17 & 19 inch. They were used in Maggies,
Admiral, Warwick & a few others. Sylvania also built early in lines
that were very good & were found in Sylvania, Philco & Sanyo.
Zenith built EFL in lines & went into almost all the line. Also sold
them to Panasonic & Gold Star for the better models. After that they
invented the FTM CRT that became the flat & square tube.
73 Zeno
LFOD !