Years back I bought a completely original 1946 B31 which had been in a barn for decades...It was basically untouched from new...That had a DU42 headlamp fitted (and combination levers)....My 47 parts list only gives a Lucas part number for the headlamp and I haven't cross referenced that as yet or compared it to earlier lists...My 1947 M21 had the MU42 fitted and as far as I know was also original....More checking required to confirm obviously...Ian
