According to the Vintage Mobile Cinema site :
"The Ministry of Technology built seven of these custom mobile cinema units in the late 1960s, to tour the country, promoting modern production techniques to British industry. The seven Bedfords were operated by PERA, or the Production Engineering Research Association. Films would be played within the cinema, with supporting displays shown in the trailer that accompanied the towing unit as they toured the nation’s factories.
The Bedford SB chassis was fitted with coachwork by Coventry Steel Caravans, utilising cabs supplied by Plaxtons (hence their similarity to Plaxton-bodied coaches that used to be common throughout the 1970s). The remote control projection equipment was placed In the steel framed, perspex-glazed dome above the cab. CSC also built the towable display trailers."
This one was built in 1962 and looks rather different from the 1967 Bedford SBs shown below. How come ?