The key start engines with points and a resistor also have that "ign 2" terminal built into the ignition switch, which serves the same purpose. There is a "R" terminal on the starter solenoid cover that provides the full battery voltage to bypass the resistor. I spent 30-something years teaching auto mechanics, including point-type ignition systems. Most Delco-Remy ignition coils operate on about 9.5 volts, so they need the resistor to drop the 14-something volts from the charging system down to prevent point burning. When the load of the starter motor is on the system, most batteries drop to 9-10 volts while cranking. The low voltage coil primary assures a good spark during cold starts.
Jerry
