they may or may not be available... rickb would know.. he's a hn parts man.
if you just need her to run, you got 2 options.
1, the oem setup was a 6v coil, and it had 2 wires run to it.. one was 12v during starting, and the other was a resistor wire from the run terminal on the key.. thus when running it had a resistive element in line with the 6v coil.
you could dupe that with an ignition resistor. OR get the correct resistor wire and keep the 6v coil.
or
just run a 14awg wire from the run and start position of the switch for the coil to a real 12v coil like a nap ic14sb that's a 16$ coil.
that coil and a few feet of wire and terminal ends will get you running.
your call
soundguy