Grant,
I think the previous experience with civilian GM trucks from “Local Purchase” in North Africa influenced these specs. See the attached document from 1940 listing the types of trucks in use by the LRDG.
Apart from the purpose built body by Gotfredson, the rest of the 1533X2’s configuration seems to be made up from off the shelf components already used for MCP and CMP trucks.
The tyre pump would indeed be the gearbox mounted compressor which was an option on MCP and CMP trucks.
Noteworthy is the specification of the rear axle with 6.17 ratio. This would be the same axle as on the C15, which has a
type of differential lock. Thus, the 1533X2 was ideally equipped for the desert, whereas the extra weight, noise and fuel consumption of an all wheel drive system apparently did not give enough advantage.
