Not sure if this is the right answer but may help.
The Euro Tunnel Exhibition that was at Folkestone had a layout (parts of which survive at the Elham Valley Railway Musuem).
From looking at old footage (links below) this is what i could see
British Rail Class 91's hauling the car/truck carraiges
Freight train based on the Class 89 "Badger"
Loco hauled German stock
Shunting loco was interesting as the one on the layout is broadly similar to what they ended up getiing (
https://en.wikipedia.org/wiki/Eurotunnel_Class_0001)
Attached is a photo of the display cabinet at Elham with some of the stock used on the layout.