This looks like the first car to get a die cast bottom on all versions. This is the non-mechanical two-tone version, It also came as a mechanical and in RAF livery as a staff car, with free running wheels. The known first here though was red painted rear lights, it was the first Corgi to get them.

The mechanical Vanguard was either primrose yellow or very pale blue/green with a red roof. This freewheeling version was only available in the two-tone; red over pale blue/green. Values are pretty high for all colours and versions. There is one variation on the freewheeling car and that is the red roof. On some it extends down the roof pillars, on later cars, usually with spun hubs, only the top of the roof is painted red. These later versions are more highly valued than the cars with red window pillars.

My model is just about OK - there is evidence of an attack with a paintbrush around the grille and I think the red may have been touched up a bit too.