Sorry the readings didn't stabilize. The following is some unwanted information but it may help the troubleshooting.
The Ignitor module is an electronic switch. It is on or off just like ignition points... which are a mechanical switch. When you connect the black wire to coil (-), if the Ignitor is in "conducting mode" (effectively switch closed = "on") then current flows through the module to earth.
If you have a resistor or resistor wire supplying coil (+), then current flowing to the coil will experience a voltage drop that you can measure between coil (+) and ground. If the current is not flowing (points open or Ignitor module "off") then you will measure battery voltage on coil (+). The voltage drop at coil (+) will only happen when current is flowing. The Ignitor module uses magnets in proximity to the module to turn the electronic switch on and off.
Try another test. Remove the magnet ring from the shaft on your distributor and disconnect the Ignitor module's black wire from coil (-). Turn the ignition on and measure the voltage on coil (+). It should be battery voltage. Now connect the Ignitor module's black wire to coil (-) and repeat the voltage measurement between coil (+) and ground. IF you measure a voltage drop (anything lower than battery voltage) replace the Ignitor module. No current should ever flow with the magnetic ring removed from the dizzy. If current is flowing with the magnet ring removed then the module is always conducting. That is equivalent to mechanical points never opening. When that happens you never will generate a spark.
Go back to points for a while to see if you can get a spark.