What then about this no. 25f Market Gardiner's VAN? May be it's because English is not my native language that I have never understood the meaning of 'van' in this respect. However, the model is also referred to as 'Market Gardiner's Wagon'. 

Hi Jacques, that detail is taken from the (undated) ca. 1947-48 US catalogue, four pages. I chose that one because it nicely shows the combination of both the Market Gardiner's Van and the 'real' Delivery Van. But this is no American exception, as you can see on the detail below, derived from the well-known Model Collector reproduction of the British 1939 Dinky Toys catalogue. 

Gentlemen,

I believe I have a good English vocabulary and use it correctly but I cannot understand why Meccano used the term 'van' to describe the Market Gardener's truck. To me a van, as Jacques says, is a vehicle that has a closed roof and sides and, usually, rear doors, a shutter, or a curtain. Even in American usage the 25f would be a Stakebed Truck.

Meccano themselves seemed to be happy to call the 22c a truck, the 25a a wagon, and the 25b a covered van! I see no logic to the names other than, perhaps, to convince young purchasers that the range of models available was comprehensive.

Kind regards

John