This is the Wrenn W4657 "United Dairies" (UD) 6 Wheeled Tanker Wagon in White, with GOLD/YELLOW letters. Introduced by Wrenn Basildon in Period 2 (Triang/Wrenn) this survived in production until the closure in Period 4 (1992). Probably one of the most popular 6 Wheeled Tanker Wagons to be used with freight operations on any "OO Gauge" layout.

WHY RARE? 

MOST EXAMPLES come in the short box format, however over the years I have only seen a few in the Period 4 Long Box (type W7304) version which this is. Comes complete with yellow plastic insert and card packing pieces .

Condition of the Tanker/box is "near mint" for their age.