The model is based loosely on the Karrier breakdown trucks that were used by London County Council to tow broken down trams. After the LCC tramway became part of London transport in 1933 a tower was added for the repair of trolleybus overhead. The appearance of the model is similar to the Karrier truck, but as no mechanical information was available the actual working of the truck is not based on any real vehicle.

The instructions are profusely illustrated with no less than 48 carefully positioned colour photographs. Sections deal with the assembly of the chassis, construction of the differential and rear axle, front axles and steering, engine, mounting the engine, radiator and dash board, gearbox and auxiliary gearbox, seat and cab floor, drivers cab and doors, cab roof and platform, remaining body details, and the breakdown crane. The 24 page booklet includes a comprehensive parts list.