I think the ammeter gets a bum rap - if anything is the culprit for electrical issues it's the connections at the firewall bulkhead connectors. For a 'normal' current draw (anything close to stock) just keep those cleaned and greased . These ammeters may have changed design in later years, but every ammeter gauge I've worked with on an old 60's to mid 70's Mopar was basically two terminal studs connected to a strip of brass between them - effectively tying the black and red wires together. The ammeter needle moves like one in a compass, sensing the direction the current is flowing. Outside of the fiber/spacer/insulating washers on the terminal studs not installed properly or breaking and causing shorts, there's nothing to wear out or short out. You could bolt the red and black wire ends going to the ammeter studs together and insulate them, and you'll have removed the ammeter from the equation.
As far as any bypass wires, I run one 12 gauge wire from the stud on the alternator back to the starter relay + terminal. That's it. I leave the original black and red wires, with their terminals (male and female) at the bulkhead connectors cleaned and greased, in place, to feed juice to everything. That's providing something hasn't already melted; then of course some surgery is needed, but even then, I leave the wires going to the ammeter. Works for me - no issues.