Yes, it should be simple. A 1974 Honda 400 has a nice ignition that does not need a battery. How hard to get one and adapt to a prop hub? What I use that is simple, reliable, and low cost is a clone 009 distributor with "electronic ignition" in it (found on ebay) and a Harley Davidson Sportster dual fire 3 ohm ignition coil (found on ebay). I just ground one plug wire from the coil and wire the other to the coil input on the distributor cap. Then two of the plug wires from the cap go to the spark plugs and the other two go to the same ground as the coil extra plug wire. Just using a dual output coil as a single output coil and wasting the extra two coil triggers. A small 12v battery runs the system. Of course the same system would work on a 4 cyl VW.
Norm Heistand my .02