[gordon]

Well the ones with the vertical booms I know nothing about, so I'll just ignore those.

The ones with the tripod booms are configured like the Chevrolet (US) K 43 Signal Corps Telephone truck - the pole setter, although the booms are longer and higher.

The Signal Corps truck had the same winch setup, tripod boom (with the centre part two sections with a sliding joint for different rake angles) and the same drop down rear supports as you see dangling beneath the CMP trucks.

It's definitely the same sort of kit, and would collapse and store the same way, just not sure if the extra height on the CMP trucks is significant or if it is just another version of the pole-setter truck.