Hi, In 1930 I believe, the size of the letters and numbers was increased to a full 3″ for the rear number plate, and the law was made to be ‘retrospective’, so earlier machines were supposed to conform to the new regulations by having the bigger letters and numbers on their plates. Quite how many obliged is another matter, in those pre-MOT Test days, and many original 1930s plates seem to have 2.5″ letters and numbers. All a bit confusing….
Brian
