The Second Lesney model of the Massey Harris tractor joined the Matchbox 1-75 series in 1957,
It was not really a new model but a reworking of the earlier issue,
The first tractor was a scaled down version of the 1954 large scale model which was a suberb toy which measured over 200mm or 8 inches long.
Starting with the 4a tractor Lesney removed the driver and made a new die to make a seperate driver casting which slotted into the tractor body, The driver casting was held in by the rear axle pin.
The rear mudguards were omitted and the underneath of the engine was recast with a void making the 4b a much lighter model than the earlier issue.
The rear wheels were a solid casting on the earlier issue but the second one had hollows cast into the back of the wheels which must also have reduced weight, The number 4 was also cast into the back of the rear wheels.
On the first tractor the front wheels had four spokes but these were rather weak and were prone to breaking around the spokes so the new tractor had new solid front wheels cast.
On the 4a the word "Lesney" and "England" were cast into the rear mudguards which had been deleted on the new model so "Lesney England and "4" cast in under the engine void.
Like the real Massey Harris the Lesney tractor was always painted red, The driver was painted light brown and the gold trim that was applied to the engine detail on the earlier issue was deleted but the rear wheel centers were still trimmed in gold.
Later all the wheels were changed to grey plastic of a size slightly smaller than the metal wheels which the model had been fitted with originally.
There is one casting variation which was the result of a damaged die and that was to the gap between the drivers arms and legs was closed by infill on later models.
The grey metal wheeled version is fairly common but the grey plastic wheeled issue is quite rare although it probably does not sell for as much as you would expect a model of this rarity to sell for.
The Massey Harris was packaged in 'B' type boxes only, It was deleted in 1960 to make way for the 4c Triumph T110 motorcycle & sidecar.
Updated: 24-07-11, Antonin Shenk has shown us two unrecorded variations, The first does not have a steering column cast in to the driver and the second shows a 4b fitted with solid rear wheels from the earlier 4a, they have been added to the listing at no 1 and 2