The Series one for sale on Wheeler dealers - has this info on its BHMIT Certificate 18th August 1954 as build date and 17th September 1954 as dispatch date -- 47102705 Destination Chemical Defence Establishment, Porton Down, Salisbury.. The registration shows as registered 1963 on the Gov website currently, so must have been - re-registered using the same VRO?
When I bought my S1 - its stated first registration was 23-5-84 and DVLA clearly stated it was not registered with DVLA till then -and were unable to give me any information between when a V55/5 (First licence and declaration for registration) was sought for the vehicle - which still carried its original registration! DVLA issued a "duplicate registration" at that time - Fortunately , Cumbria Records office has the correct date of first registration - for the Land Rover - and with BMHIT certificate back up also - now the V5 states the "declared" correct date of first registration as 26/11/1953 - BUT as far as DVLA are concerned - my S1 didn't exist before 23-5-84! As they don't hold any of the old paper records from County Councils or Vehicle licencing Offices.