Those were built by County Commercial Cars in the UK based on a Ford power train. The Super 6 was a 6 cylinder and later the Super 4 was a 4 cylinder. I had the pleasure of perating a Super 6 in about 1965 which was built prior to the blue line introduced in 1964. The power trains were all B serial numbers from the Basildon UK plant. Not many of them came to north america. The identifying data is stamped on the casting just aft of the starter. Post that information and more help will come.