With nothing running, voltage at the ignition terminals on the ballast resistors should be the same at the battery voltage.
Shouldn't. There may be small differences due to emissions related devices (like the timing device mentioned above that operational schematic)
The coil windings and the ballast resistor are matched pair. So if the '74 FSM says ballast resistor should be 1.4 Ohms and the coil primary .75, then yes change coil.
Hoppy answered that. Sketch it out and see how it operates. Since your using an electric choke it may be useful. If you've hooked up your electric choke so that its drawing off power, that could be your issue.
Blue wire supplies power to the alternator's field windings (rotor). It is used by the voltage regulator to sense system voltage and decide what to do. Blue wire should always be at system voltage when the key is in Run position.
The ECU does the same as points. It opens and closes the primary circuit. When its closed, current flows through the coil inducing a high voltage charge to be developed in the secondary side. When it opens the flow stops and the high voltage charge goes to the distributor.
It should connect to the ignition circuit.
There should always be power present at the coil positive when the key is in Run or Start. The voltage at the coil positive will vary depending on whether its flowing and whether its coming through the resistor (run) or direct (start).
When the engine is running, the alternator supplies power that is regulated to be around 14 Volts.
When current flows through the compensating resistor, the voltage drops a little. A little more when hot. Reducing the voltage keeps the coil from overheating.
In Start, the battery supplies voltage around 11 Volts or less, so no compensation is needed.
This might clarify that operational schematic.
View attachment 1715354889
In the back of the Electric section of your 74 FSM is the wiring diagrams. Use those figure out the connections.