Chassis number on frame
At the time of manufacture/assembly all vehicles were marked on the chassis frame or later body, with the original engine's number, and locating this can involve a certain amount of very careful examination. Please remember that this is the 'original engine's number' as factory fitted. Upright models, including Model Y through 103E all had the number stamped into the flat horizontal surface of the main right hand chassis side rail (left side for lhd), just ahead or beside the cross member rivets of the diagonal brace, just to the rear of the steering box. The distinctive leaning characters are sometimes preceded by a star, then Y for 8hp, C for 10hp, then the numerals, sometimes finishing with a star. This can be read by standing beside the vehicle and once the bonnet is lifted, looking down to the chassis rail.
100E and 107E models usually had the number stamped around the plate, which is held in place by three nuts, which forms the suspension unit upper mounting on the driver's side in the engine bay.