Yes and no, farren.
The wagons date from around 1964/65 onwards, and even Hornby's dated model was introduced around 1966 or thereabouts. That gives a little overlap in the steam era to the end of steam in 1968.
However, the wagons were air braked and only diesels or electrics so fitted would be seen hauling them. They could be seen side by side with steam.
EDIT: Sorry about the double post earlier - I have now deleted the other one.
Edited by SRman, 22 July 2014 - 03:39 .