Mystery Wickham kit

Earl King is one of the people responsible for me being involved in railway modelling. His enthusiasm pointed young Phil at the hobby so it's partly his fault. 

Anyway, a few days ago, he drops in. Having seen my pieces in BRM, in his pocket is a mystery 7mm scale Wickham trolley kit. It's obviously a very early multi-media model but there are no makers marks or other details to identify the manufacturer.

The floor is nicely moulded and complete with some interesting "junk" detail. Underneath there is a rectangular indentation to accommodate a SPUD for motorisation. That places it late 1980s at the earliest.

So, can anyone suggest a manufacturer? I'm going to build the model anyway but it would be nice to know.