Why pay for one? If you apply to the DVLA for an age related number and you have proof of the age of the car (you will need a LMC dating letter) you will be given one for free!
I understand Elaine approached the DVLA and they were not prepared to play ball saying that they would only issue a plate reflecting the year the car was first registered in the UK. They suggested she buy one at one of their auctions!
When I bought my Dilambda the previous owner had not transferred the registration onto the DVLA computer in the 80s and it came with no V5. When I rang the DVLA to ask their advice as to what I should do they looked up the original number, said it was available and let me have it for free! I believe that ERF 294 is a 1937 number which is when my car was first UK registered and not a 1932 number which is when it was built. My V5 shows the first date of registration as 1937.
As far as the DVLA are concerned date of first UK registration seems to be the all important determining factor.
Has anyone here applied to the DVLA and been issued a registration number earlier than the date of first registration as it appears on the vehicles V5? It is of course perfectly possible to transfer an earlier number you own.
Robin.