I have found a reference in the AWM commander diaries -which includes a dozen illustrative black n white photographs- of the RAE appraising 2 Unimogs whilst constructing an airfield at Borneo.
In Malaya, FARELF operations, Sep 1964. Yes, 64. The existence of Army Halflingers in Vietnam could therefore get more credence.
ARNs 97016 and 97017 were used for about 65 days, however that included 20 days stand down whilst there were torrential downpours. The airfield became a sea of thick mud.
You have to download the .pdf file and then proceed to page down -once it is finished downloading- to about the 3rd quarter.
The RAE report says each of the 2 mogs did about 400 miles in service at an av 10 mpg. Could carry 2 x 44gal drums each.
LINK:
https://www.awm.gov.au/collection/records/awm95/4/3/awm95-4-3-8.pdf7 Field Sqn, RAE, Sabah, Malaya
Sept 1964
2/2016
Its now migrated by the new record keeping system to this pdf:
https://www.awm.gov.au/images/collection/bundled/RCDIG1028478.pdf.