Jacques,
The inclusion of the two little brackets on the front cowl depends on the date of production and the make. You don't seem to see them in images until some time in 1943, so I suggest a design change happened during the first half of 1943, but I'd have to do some more study of images to confirm that belief, and have not found any documents supporting that theory. Of course, imported trucks from the early cab 13 supply contracts (such the in the 55xxx series) were CDN made and did not have the little brackets.
Both Ford and Holden were supplying utes with high canopies to the Army around that time (late 60/early 70s). A scan of the later volumes of AWM126 will give you a good idea of what was being purchased during the period up to 1972.
Mike
