Looks as if you have put an old style plate on a 1973-'79 bike, that can stay, but if its 1980, it has to be changed to be post 1973 style. Why anyone changes a safer later reflective plate for the early type beats me. Also this 1980 date looks like a distinct cut off the prevent any over 40 year old vehicle in the future displaying the earlier style plate.
A shake up in the number plate business as well, as we exit the EU.
Swarfy.