Not getting 12v to coil on start ('73 Dodge W200 360La)

There never should be 12 Volts at the coil.
On a standard (kettering) system like the factory ecu or points, the voltage in Start is battery voltage - which should be higher than 9 Volts when the starter is turning, but rarely as high as 12 Volts.
With the key in run, the voltage will vary from system voltage (points open) to something less than that as the current flows through the 1/2 ohm resistor (points closed).

With a capacitive discharge system, power goes to the coil primary circuit when the capacitor in the CD box discharges. The coil than transforms that pulse into high voltage pulse to the spark plugs.