I've found this VERY interesting as I'm building a 1/4 scale model of Henry Fords first car, the 1896 Quadricycle. I would like it to be as near original as possible and also for the engine to actually run, 'though only for short periods.
The posts above give me a good basis to start on the ignition system.
View attachment 128035
My start on a coil for an igniter.
I had some brass and a length of cast iron rod.
After silver solder to hold the brass to the cast rod and truing up the brass I coated the cast rod and brass with some epoxy to insulate the enameled wire.
The epoxy is hardening on the wire while I took this pic. I Left the lathe running at a slow speed to prevent runs and drips.
I don't know the resistance of the coil as wound.
An article on igniters and magnetos, etc