Far left is a very early prepro with sloping grille and 26 spoke metal wheels (as Y13 Daimler). By far the best looking model.
The three in the middle have dark maroon seats/grille. The red/yellow & metallic blue have prepro baseplate castings. The other two are standard models with trial seat/grilles. These all have full copyright dates and Y numbers despite being very early in the development of the model, especially the cream/white example.