The Lesney model of the 8a Caterpillar crawler tractor joined the Matchbox 1-75 series in 1955.
It had grey metal rollers on flat head crimped axles, the tracks or treads were always green except for the final run which had grey treads that are usually found on the 49a halftrack.
There were a few different colour schemes used on this model,
The first was deep yellow with yellow rollers and axles and it had a red driver with a black hat, The main colour was spray painted but the additional trim was hand applied by outworkers,
After a short while the assembly and painting process were changed so now the painting was done before the rollers and axles were fitted so the roller and axles were now left unpainted. The next colour used was a pale yellow and the driver was still picked out in red with a black hat.
Soon it was recoloured to orange and the driver was left in body colour but still had his black hat and the grill was painted gold, Fhe final and most common colour was yellow with silver trim to the grill and the drivers hat was black and on the final issue in this colour the silver trim was omitted from the grill.
There were no actual casting variations but as the dies wore the area between the engine and the cowling was gradually filled.
First the area behind the engine filled, then the area above the engine towards the front filled and finally the area above and to the rear of the engine filled in.
It is a fairly common model although the orange version is hard to find and the variants with red painted driver are quite rare,
This one was packaged in 'B' type boxes and it only stayed in the range for three years,
In 1958 it was replaced by the next caterpillar crawler the 8b.