A highly detailed model of the British railways Mk.1 series post office sorting vans, built in the 1950s to re-equip the Royal Mail travelling post office trains.
This model represents the Travelling Post Office coaches from the corporate era of British Rail, painted in the standard blue and grey livery. This is the plain side of the coach, the sorting pigeon-holes were on this side of the coach.
Note the red painted late posting box in the side of the coach. Members of the public could post mail for the destinations served by the travelling post office train up until the time of departure at an extra charge. Latterly it seems this service was used mainly by enthusiasts collecting the special TPO cancel stamp.