The Trux website has a section on British ASSU
here - note this is for the british unit(s) but Canadian will no doubt be very similar. Also look at the page on 2nd Tactical Air Force -click on "21 Army Group", then on "Army" then you will see 2TAF in the list that drops down. Also Note that the Trux website will shortly be reorganised in a different structure.
Noel