If you really wernt all for originality you could probably use the points to switch 2 car ignition coils powered with a 12v sla battery, I did that back at the very beginning of my mower collection with a full crank victa.
I do have saved somewhere here how to do a twin powertorque coil conversion, it however is a patch not a fix, generally it will start on one cylinder and the other will pick up once the engine gets a little speed behind it.
