I have only uncovered two brochures for the 1-Ton models.
The first shows the “mule” prototype vehicle, with the headlamps in the grille panel. Sadly this brochure was of little use as the production models had the lamps in the wings. The vehicle in the photos also has Rover, not ENV axles, a six-cylinder exhaust system and standard spring mounts, not the extended types normally found on a 1-Ton. As detailed in the prototypes page, this vehicle was basically a photographic mock-up with wooden blocks between the axles and chassis to fit the 900×16 tyres. The vehicle was a standard six cylinder truck cab which was eventually sold on.
(pictures from http://www.landrover.vlothuizen.nl/show/list/2016-4.html)
This is the later brochure for the post April 1969 versions. The vehicle in question has narrow sills with the lamps in the wings, making it later than the initial production batch of 1-Tons.
The registration CXC181G was used on various different Rover cars and Land-Rovers, it was probably used for photos in and around the factory, then sent to its intended owner.The factory registration book shows a Mid Grey 1-Ton chassis number 22900022G dispatched to Works Engineers, and registered MXC691H, this is almost certainly the vehicle in the brochure photos.
Interestingly the cherrypicker shown in the brochure is built on a standard IIA 109″, not a 1-Ton model. The 7.50×16 tyres are quite obvious. I have never seen a series III 1-Ton Brochure – were they ever produced?
A version of the later brochure exists with the text in German. The photographs appear to be identical to the English version. It is unexpected to find a German version as no 1-Tons were ever sold in Germany, not in any other German speaking countries aside from one vehicle sold in Switzerland (which even then may not have been for a German speaking customer)
The cover is the same as the English version and has English text.