The Zenith Trans-Oceanic series of shortwave portables would stretch from 1941 through 1982, with tube models produced until 1963.

Zenith K725 By the 1950’s radios were everywhere. FM broadcasting started to gain popularity with its high fidelity. Table top radios such as this one provided both AM and FM broadcast bands in ...

FM radio came into being in 1933, improving reception even further and allowing for stereophonic broadcasts. By then, radio had become the primary source of home entertainment for households ...

But we think it is really a 6G601 which is a proper Zenith model number. According to [Jeff], 225,350 of these radios were made, and you can see that it closes up like a suitcase.