Just a thought here on checking the voltage at the coil. You will only get a voltage drop from the resistor when there is current flowing through the circuit, that is, when the points are closed. When the points are open, you will have the full 12 volts regardless of whether you have a ballast resistor(or resistance feed wire) or not. Check those points also to make sure they are grounded on one side(and only one side). If they aren't, you aren't going to get any spark out of the coil.
