It sounds to me like you did well .
The rust on the Hall Effect Generator was the most likely culprit IMO, I have saved a few of them by gently and carefully wire brushing the rust off .
The Hall Effect Sensor is fairly easy to test, use your multimeter set to milli volts and disable the power to the ignition circuit ~ crank the engine and you should see some meter action ~ this is why I still use analog multi meters : they'll wiggle the needle when a digital meter may not show anything .
FWIW, fuel and air filters should always be changed every 12 months or 10,000 miles, I've had the exact same problems you did too many times over the years ~ no one ever changes the damned fuel filters
.
Might be time to do a
HOT OIL & FILTER CHANGE too...