Another "small and cute" radio, also an Emerson (model 747) is shown below. It is a battery-only portable about 6" x 3.75" x 1.5". It uses flat sub-mini tubes, similar in size to those used in tube hearing aids. ca.1953.
Emerson 747, Sub-Min Tubes on Flickr
Tube lineup was 1V6 converter, 1AH4 if amp, 1AJ5 detector & 1st audio, and 1AJ4 audio output (about 45 mili watts). In a later version, the audio output tube was replaced by 2 transistors, in push-pull.
jr