The rule about newer number than car was only introduced some time after the change to the numbers system that identified the registration year. Prior to that if you had a personal number, when you swapped it off the car, another number for it was issued by the authority where you happened to live. I assume that's why the 1910 Star I had was LL776 which was issued in 1914 and I know it's what happened to a 1962 Daimler SP250 which was 6798 PP by the time I got it in about 1972.
Actually, yes, that's true - I'd forgotten!
Originally when you took off your personal number on selling the car it just got a brand new one, and "age-related" plates were not yet a twinkle in anyone's eye! Hence a car could look much newer than it actually was if it was re-registered for any reason.
