Separating the car from the numberplate will devalue your vehicle - so you need to be sure that the plate is worth enough for you to come out ahead. There are plenty of online numberplate sellers who will give you a valuation, but it's worth taking with a pinch of salt. You also need to remember that it can take a very, very long time to sell a numberplate. If you're convinced it's the right way to go, contact the DVLA and put your existing numberplate on retention, your Cowley will then be given an age-related numberplate. For what it's worth, I always think it's a shame to separate a car from its numberplate - in this case, it's worn it for 86 years.