Have seen a number of videos recently of these units in and around Glasgow in the 80s as 3 car units and was wondering if there are any design differences between both outer driving cars?   It would seem to be a good opportunity for a manufacturer to product a 3 car set if it only requires 2 x toolings.  One for a driving car trailers and one for the central powered car with the overhead equipment.   Am I missing any key pieces of equipment on the outer cars or are the bodies