Interesting question, Richard. More than once, people looking at my Mk A Bond have said things like "Oh yes, it's got the 'B' on the hubcaps - only the Mk A had those ... except of course the Berkeley"
... but I don't think I've ever seen a Berkeley with them! They usually have heavily-coned chrome trims, and if there's a B on the spinners, it tends to have two circular 'holes' in the B (as in the pic below). Incidentally, my Mk A has the plainer of the two Bs you show. That is, the upper one in your photo.