Contrary to regular Meccano practice the scheme for this topic is rather simple. Examples of the 1940s have the satin finished black hubs. Those for export only, of the early 1950s, have the coloured hubs. The latter also coincide with the softer, nowadays often more or less bent windscreens.
The ones with black hubs were discontinued in Britain (and the commonwealth countries?) around 1950, but will be found (as continued with coloured hubs) in the export catalogues for ia the Netherlands and the USA until 1954/55. On the other hand these export models will never have the nice treaded black tyres, which some of the black hubs examples do have.
No wonder that our American friends often have the examples with the coloured hubs and British collections include in majority examples with the black hubs. Of course the easy international trade in models mix them up more and more nowadays.
Kind regards, Jan