This is a superb example of the RARE Wrenn W4665 "Saxa Salt"  wagon in the darker orange colour, running number 248. This is provided in a Period 4 (type W7304) long box. These were introduced by Wrenn, Basildon, in 1987 with only 519 manufactured before the 1992 factory closure, however most were issued in the standard short box hence I would classify this as Rare.

NOTE: This was the same colour variation as the Hornby Dublo dark orange, its predecessor!   

The Wagon comes with WA1 yellow plastic insert and stapled yellow card pieces (2), and is correct for the Basildon issue period.

Wagon/box is "near mint" for their age.