[David_Hayward (RIP)]

The top appears to be a Holden-assembled Bedford WHG, circa 1936-7 Model. I do not know much about Bedfords but it is very similar to a 1936 Model that was submitted by Vauxhall Motors Limited to the 1936 War Department Trials in north Wales, though the Vauxhall version had different, WD-style wheels and tyres. The same truck may have ben trialled in 1937, as a WHG was used as well as a lwb WLG. The wheels look like Chevrolet ones of the period and may be Heavy Duty ones as fitted to contemporary civilian chassis.

The middle front truck appeared to me to be a British Fordson 7V forward-control truck. Norm Darwin's book on Ford in Australia, page 106 has a small photo of a a 'NEW DEFENCE UNIT' promo. These Dagenham-sourced 1936 trucks were assembled at Geelong for the Defence Department as field artillery tractors, and were 'very rare, few were assembled'. The FAT had a crew of seven plus ammo and had a 105-inch (shortened to) chassis with centrally-mounted fuel tank. The 2-wheeled gun transporter mounting the 18-pounder QF gun was designed so that it could be towed up to 35 mph. Is the rear truck another Bedford?

Search also under 'FORD TRUCK'...I found some nice CMPs.