How about the Oxford Diecast Land Rover Series II SWB Hard Back Royal Mail in 1:43 Scale? This model is suited to Royal Mail enthusiasts and also anyone interested in Land Rovers.
The Series II Land Rover was introduced in 1958 and was manufactured until 1961, when it was replaced by the IIA. Whereas the Series I had flat sides, the Series II can immediately be identified with the rounded side panels, which allowed for the wider track of the vehicle. Coming in Short and Long Wheelbases with numerous body combinations including fixed roofs, canvas roofs, open tops, station wagons etc.
The Royal Mail fleet is still one of the largest fleets of vehicles in the UK. The use of mailvans expanded during the 1920's and 1930's, initially Fords, then Morris before a whole variety of other vehicles were used. The Land Rover ruggedness made it an idela choice for use in the countryside.