We've had YOM plates allowed here in Ontario for some years now, but the greatest difficulty is locating plates with numbers not in current use (the rules say they must have been unused for at least a year). The other problem is that many of the number combinations originally issued for automobile plates have now been assigned to other kinds of plates, such as trailers and snowmobiles. I have about six sets of 1965 plates, including one band new set, but none of the numbers were usable as they were currently assigned to other types of vehicles. I was ultimately lucky enought to find a pair in good condition with usable numbers and had them registered for my '65 Vette. Ontario doesn't restrict 'restored' plates, although you have to send the plates to the Transportation Ministry for their approval as to colour/configuration/condition.

If significantly different from current plates in colours etc, they really add to a restoration.