Radiola models were all made between 1921 and 1931. During those years
"The Radio Corporation" (as it was then known) had no manufacturing
faculties, all Radiola models were made by companies like GE, Westinghouse,
Graybar, Brunswick and a few others. RCA also offered radios without a
"Radiola" designation, such as the well know
Radiola model would appear in the RCA line after 1931 until the late '40s.
These were generally models from RCA's regular line-up with "Radiola"
applied to the radio and offered during a special promotion celebrating a
milestone event or anniversary.