The Royal Ediswan product mobile appears to have been built on a Model TT Ford Truck chassis. The Edison Swan Electric Co. Ltd. was located in Ponders End, Middlesex, England and manufactured and sold a full line of all types of electrical devices in addition to Fullolite Lamps.
See it and a couple of other oddballs today on the theoldmotor.com where we have been working hard on a new and improved version of the website that we hope to roll out early next week.
The roots of the "Ford has a better idea!" campaign.