The description below is taken from the Airfix catalogue this kit was first seen in. There is also extra information underneath the main catalogues description including the changes to the name of this kit in the catalogues.
Airfix Catalogue description:The Prestwin Wagon carries bulk powder in twin silos and discharges its load under air pressure. Holds up to 20 tons. This scale model has all the intricate detail of the real thing. 64-part kit. - Taken from the 3rd edition catalogue (1964)
Airfix Series (first appearance): 1 Rarity of early version: Scarce First Issued: 1964
This kit appeared in these catalogues:
3rd Edition (1964) Ref: R10 4th Edition (1966) Ref: R10
Just some of the kits listed...