Many collectors have some knowledge of the two versions of the Dinky Toys Foden trucks, that the English Meccano factory made. The first, early version was made from 1947 through 1952, and was then replaced by the second version, reflecting the newer style cab. Besides the new look, Meccano also introduced several other changes: new recessed style Supertoys wheels are very visible and obvious, but Meccano also choose to improve the overall strength of the models, by also changing the axles and also the way there were supported.

First, they greatly increased the diameter of all Supertoys axles, and, secondly, they totally changed the way the axles were retained to the chassis. Instead of utilizing a sheet metal clip, they were now inserted through a hole drilled in the chassis. The photo above shows the undersides of both the first and second style Foden Flat Trucks with Chains, clearly showing these important changes.
And this photo clearly shows the difference between the two cabs and the styles of wheels.

For a more in-depth look, please see these additional articles by me: