The same applies in France. I can put a black/white plate on my '87 Kawasaki, the 'Véhicule de Collection' category starts at 30 years old here but it has to be registered on the Carte Grise (your V5) as such. For that it has to be accepted by the Féderation Française de Véhicules d'Epoque.
Curiously it allows me to ride in pollution controlled city and town centres without having to pay or have an appropriate badge.