But the question is : was it called Sherpa in South Africa ? This one has the late 80's plastic grille. It could be a Leyland-DAF 400 or a Freight Rover, for instance, or another name.
High roof, twin rear wheels make this a Freight-Rover 300 series as the earliest model. Leyland Sherpa would be too early as it was only available as the smaller 200 series.
Later versions Leyland-DAF (or DAF in some countries) 400 then LDV 400. All UK names.