oh yes i remember those things
i had a service truck set up in the early 80's where i used 4 grp 24 high capacity batteries
and a 4 post delco series parallel switch, controlled with a cord real and push button switch.
had 50 feet of 2/0 welding cable with tweco connects and vicegrips for clamps
i could pull up to any truck on the road connect, and have them hit the starter
at which time i hit the series parallel and it would shoot about 2000amps at 24volt nominal
to the starter.
that would yank em to life in a hurry, all except the old 1693 cats when it was about -20F
it had enough to light em up, but it would make the cables jump in the snow seeking magnetic north.
i used the smaller grp 24 for fast recovery between jumpstarts
i remember building the thing wondering whether it would pay off
i made a lot of money with that thing for the 3 winters i was in that part of the country.
couldn't use that sort of setup today, computers don't like 24 volt spikes on a 12 volt system
the system you are referring too, used an electric start 16hp B&S, and 4 heavy delco generators
that were able to put out about 200amps each long enough to help start a truck.
and yes they were quite expensive iirc
yes those were the good old days, i get cold feet just thinking about all the long hours
thawing trucks, setting fires under fuel tanks to degel them, more fire under the engine's to warm them.
when it gets below zero, it is darned hard to burn down a truck,, even if it is dripping in oil!
bob g