The chassis number says it's one of the earlier batch of T203 1940 military VF production, obviously not a VF 402 as no winch front.
The cab and chassis is actually surprisingly common, but very few turn up with the original cargo or dump beds.
With your permission I'll copy the image and add it to my survivors list ?;
http://www.gwim2.pwp.blueyonder.co.uk/vc200401.htm
Not a British contract truck though, as far as I know.
About 1500 did come to the UK, chassis all above 8833896 according to David Hayward. I'm sure there were similar 4 x 2 trucks procured too.