It has been suggested that the old Beverley records were handed to the Army Museum. I found some excellent records relating to Rootes' wartime production in the Museum of British Road Transport, Coventry. I believe that there are some Morris records in trhe MRC at Warwick University but I am out of touch.
In addition there are papers and photos relating to airborne MCC, CMP etc. trucks in the Airborne Forces Museum in Aldershot. Their collection is extensive and would take days to go through all those filing cabinets.
Alan Brown