Hi Pete, This Crown Cork Foden photo looks like an official Foden one taken at their usual photo shoot location at Elworth. Note what looks like one of their own works fleet on the right and the sloping bonnet line of a new look Foden bus or coach on the left of your photo. Interesting that Crown Cork became connected to Metal Box Co in later years and are still in existance in the Middle East producing drinks cans.
Cheers, Leyland 600.