The AA Services Bedford was always No 408, but the casting changed over time when Bedford gave the old CA a facelift. I'm old enough to remember this happening. Most delivery men to our farm who used vans used the Bedford CA and I remember the gradual change as they replaced their vehicles. Gradually the old one (which always reminded me of a pig for some reason) was replaced by the new smarter one with a mesh grille rather than the open bars of the early one.

On the left is the 1957 version - the one in the pictures on the right is the later casting, the differences being that the early one had a split screen, larger openings in the grille and a plain roof. The later ones had transverse ridges in the roof, presumably to reduce drumming. Later Corgis of course will have moved from the early flat hubs to the spun hubs, but that is a less reliable method for differentiating between the models as the change in casting was not exactly concurrent with the change in wheel type.

The Bedford AA Van was released in June 1957 in the early casting with the split windscreen. In 1959 the casting was changed. The new casting has a one-piece windscreen and had ridges cast in the roof. The radiator grille detail was also changed. The new casting remained in production until 1963. Later releases in the second casting with turned hubs tend to get better values.