Count me and my family in on this one. My dad had a 6 channel tube Pearce Simpson Companion installed at his shop and two Sentry II mobiles installed in his paneled truck and old, blue Plymouth Satelite I think in 1965 by the radio shop that was in the boatyard he had his business in. Different times back then. Those Sentry's I'd later discover were only a hair over 2 W, but back then, he had some great coverage with whips on the vehicles and the antenna was larger then a 1/4 wave ground plane at the shop. They used the radio back then for coastal marine pre-vhf days when many pleasure craft had them for local comms and MF AM for offshore communications. The radios were also used for parts runing and they had a pair of huge, all metal walkie talkies that were 1 W that they used from the docks to the shop.
That came to an end about 1970 when CB became too congested with chit chat and many expensive channel changes and he opted for a business band radio system as the business grew. In place of the CB, he had first a Raytheon that went nuts with intermod and later a Harris VHF marine unit that looked like a business band unit installed in the office for local ship to shore. By that time, most boats adopted VHF with channelized radios.
My dad was a by-the-book type, ex-mil guy and followed FCC rules to the letter. We didn't have one at the house. CB started to get out of control from it's original concept about then. Until that time, marine occupied a good part of the day traffic as did some construction and business use with callsigns. The chit chat started at nights, primarly with the boaters out in the bay and people who had units at their homes or lived on their boats, but not like it became steadily out of control after about '72 and totally nuts after '75 when the rebel trucker phenomonen hit the scene. I wonder if the 50mph speed limit was never imposed if this would have ever happened? Even so, I was never aware of the magazines promoting hobby type operation until I started working at RS in '72 and saw how companies were promoting CB's much like you'd see in QST or CQ magazine, so there must have been a hobby component well back to the 60's when these magazines were founded. Maybe we were different down here with Marine dominating the use and most of the CB dealers were marine outfits.