The aircraft returned to its departure aerodrome after suffering a complete electrical failure. Emergency extension of the gear was attempted, but during the landing roll the nose leg retracted, which resulted in the nose and propellers striking the runway. A written checklist was not used prior to departure and the generators were evidently not switched on. The electrical panel and the generator warning lights are obscured by the control column. Emergency gear and flap extension is achieved using the same winder which is placarded "Flaps-push handle in, Gear-pull handle out". Investigation revealed that although the flaps were in the fully down position the gear was only part of the way through its extension cycle.