Curiosity is going to kill me. I just checked the '73 Dodge FSM. Ammeters for all. B-bodies with optional 65 amp alternator connect wires to the ammeter through a grommet. The alternator side goes back out through that grommet to a single post terminal block. I kindof like it.
There are remote shunt examples too. The amp gauge didn't have the 2 large wires to it. That gauge is attached to the circuit board like any other gauge.