Pertronix III set up
Ignitor III should have its own dwell control IIRC.
How reliable is it. I don't know.
My suggestion is this. Go buy a half dozen piggy backs terminals.
Use them to jumper the Ignition J2A & J3 wires together at the ballast.
J2A is ignition 'Run' power and J3 is ignition start power.
Another way to jumper them is two 1/4" wide male terminals. Then insulate and zip tie them so they don't move and chafe around and don't ground.
Then you can go back easily if it dies.