I don't know about how they were originally setup, except that they were set up with generators, not alternators, and that's a different ball of wax.
The 1-wire alt's are used on tractors ... a much simpler setup and not of much use for our trucks (unless maybe if it's a show truck and never gets driven).
The absolute
best way to setup your engine area and your truck's electrical distribution ... as far as I'm concerned ... is with a power station under the hood (terminal blocks) -- like
THIS - Click Here What I love about the Delco 12si (aside from mine delivering 100 amps) is that, with a Delco regulator built in, it monitors everything very concisely -- even to the point of sending
lower voltage when the battery gets hot (like in summertime) ... saving the life of the battery and everything else in the truck, including wires, etc.