Probably some of the earliest Technicals were used by the LRDG :
This is a posed photo, but note the passenger side MG has no trigger - that's because its a Vickers K model salvaged from an aircraft and the firing mechanism is worked by pushing the home-made shoulder stock forwards.
The LRDG & later SAS liked the Lewis MG because its high rate of fire worked well when firing on the move. Plus the pan magazines fitted nicely into an army issue biscuit tin for easy storage
Not that the LRDG were the first people to modify their vehicles...