Just a thought: Most point systems run a resistance of some kind between the switch and the positive side of the coil to extend the life of the points. Have you checked voltage at the positive side of the coil? you should have pretty close to battery voltage when cold, dropping to about 9 volts when running. You might try hot wiring straight from the battery to the positive side of the coil to boost spark energy, at least to try to get it started. If the ballast wire/resistor is bad, your voltage at the coil wire might not be enough to jump the gap between the tip of the rotor and the contacts in the cap.