It's likely that the plate will have some value on its own but it'll depend on the exact letters and numbers. Classic cars with their original plates are more desirable, so your father will have to consider whether the value of the plate will outweigh any potential drop in the value of the car. It's worth bearing in mind that, to transfer the plate off your father's car, the Lanchester needs to be able to move under its own power, and must have been taxed or SORN'd for the last five years.

We'd recommend speaking to a classic car auction company. A good one will help your father achieve the best possible price for his Lanchester and advise on whether it's worth selling the plate separately. Collectingcars.com would be a good start.