BACK TO THE CORSA

On a higher-resolution scan of this picture, the 1966 Ontario plate is clearly visible.  I was toying with the idea of putting a vanity plate on the car with that number on it (provided, of course, I find and buy one).  There has recently been legislation in Ontario to allow for year-of-manufacture plates to be put on collector cars.  This makes me wonder what would happen if your car was a '73.  A lot of the old "'73 - Keep It Beautiful" plates are still on the road with half an inch of stickers on them.  If I bought a '73, could I use a currently-valid (but old) plate on it but treat it as YOM?  Would I have to keep putting stickers on it?

The other issue is that mid-60's plates use the same numbering scheme as current trailer plates.  Makes using them a little dicey.  Fine on '50's cars, though.