Morris Minor Owners Club

Does anyone know if the original County Council records for the MM registration numbers issued around 1948 to 1951 still exist? If so where are they held?. A member has just bought a lowlight with an OMM reg and would like to trace its history.
I know OMM was a batch of numbers used by Stewart and Arden , maybe their sales records from the early 50s exist somewhere.
Bryan

The vehicle registration / taxation records for Middlesex county council are held at the London Metropolitan Archives: http://www.cityoflondon.gov.uk/things-t ... fault.aspx