If you do a search for replacements the most common are MSD (although some have had multiple failures of various components) or Duraspark. I'm using a Pertronix distributor but it doesn't fit under the screen. Diameter is good but it sits a bit high. You may be able to install a Pertronix unit in your existing distributor.
Various threads:
https://pantera.infopop.cc/topic/electronic-ignition