My father sold Halicrafter Ham and CB sets then ,I can still remember the license we had 20W41939. These CB's had the high voltage power supplies and where quite large My family and my uncles family went on a tripe in 1961 dad had a CB in his 1961 Pontiac, he install another CB in Uncle Al's 1959 Chevy.
There has been since the 30's two way mobile radios and mobile telephones somewhere I got an artical on ,mobile radio,showing one installed in a 1949 Chevrolet Stationwagon.
In 1958 there was alot of cars/trucks with 6 volt systems still in service,I would think there would be CB's available to operate on 6 volt. Many[including transistor] after market radios back then could be operated on 6 or `12 volt and positive and negative ground,
