If you are not a stickler for originality you can use a pre war Lucas MO1 magneto (ring cam type not the later face cam type) Machine away the drive train casting, machine 10mm off the base to bring the spindle height down to 35mm and then drive the dynamo with a pair of toothed pulleys and a Megadyne belt. I have an original magneto for my Comet rewound and sitting on the shelf but prefer the Lucas magneto as I get a better spark. I should add that I have gone one stage further and used a post war MO1 body (with Nifal cast in magnets) as this is better than the plate magnets in the early Lucas, Miller or the BTH instruments. My rewound Miller dynamo gives ample charge but at some stage I will try using a 50watt Miller in place of the 36watt one. At this point I think that my fellow Mid Glos section member and Series A owner, Stan Chappell is having a heart attack after reading of my modifications! Brian Werrett.