[Mike Cecil]

Nicely deduced, Tony.

To add a little to the Sunshine Roof discussion, GMH produced the 'Roadster Cab', as they called it, for wide-track 8441, 8442, 8443 and 8444 chassis (Aust cab model number 41/5410A) and for the narrow track 8421 chassis as cab model 41/5610A. But as we have seen, the Roadster Cab was primarily used on the 15cwt.

The canvas demountable doors, however, were developed in response to climatic conditions. GMH engineers were tasked with coming up with demountable doors for increased ventilation following a recommendation from GMH after road tests on the North-South Road in 1942. The re-design was then incorporated in production from 1944 onwards: the cab became the 1944 (Aust) Pattern cab, with the '44' prefix to the GMH cab model number. The '44 Cab' also included the wide-back seat, with 2 extra inches added to the top width, and a redesigned curtain bag to accommodate both side curtains and doors.

I think you are seeing it dominant on late-production specialized vehicles because by then, most of the standard GS type contracts had been fulfilled and the contracts still to be completed were mainly those specialized vehicles - ambulances, the tail end of the No.9 artillery tractor production, tippers, and the like.

By 1944, GS CMPs were being rapidly displaced in jungle-scaled units by vehicles of US origin, and there was an over-abundance of GS CMPs available. CMPs, however, still dominated in the specialized roles throughout the Army, and hence there was still a demand for them.

The demountable door was produced as both a new production (complete cab) item and as a retrofit kit, but only those units still equipped with CMPs and in environments hot enough to warrant the conversion work ever considered installing them.

Mike C