The last of the six articulated models in the Benbros Mighty Midget Series was No.48 Flat Truck with Chains and it is the most sought after. 

The first version of the trailer was a smooth-floored casting as with several of the articulated models. The 'chains' on each side were metal bars on posts and were cast with the trailer. It was fitted with unpainted metal wheels on round-head & crimped axles and had the usual Bedford coupling arrangement. There was no identification on the trailer.

This first issue with the smooth floor was painted beige with the chains being picked out in red trim. It was coupled to a green cab. 

Benbros re-cast the trailer after a short run and gave it a ribbed floor but otherwise it was much the same. The beige colour continued with a new blue version being added, both with red trim and metal wheels.

With the appearance of black plastic wheels, No.48 continued to be produced in beige and mid-blue but the trim changed to silver.  Some of the beige trailers were just painted on the upper surfaces leaving them with a cream or off-white undercoat underneath.

Finally, two new colours were added, a darker or mid-blue and dark-red, both with silver trim and black plastic wheels.

The Mighty Midget box for No.48 called the model 'Articulated Flat Truck' and in the picture there was no sign of the chains, but there is no doubt that the model was improved by having them added.

Despite not having many variations, No.48 Articulated Flat Truck is scarce and the first issues with metal wheels and red trim are all very hard to find.