That was likely a GM Holden truck (not a ute!) from Australia, hence the RHD. Right-handers were also exported from the US and Canada from the early '30's to the late '70's, so it could be that, also. American car makers were busy building cars in South Africa during this time, as well, so the source could've been any of them. With the flip-out windshield, though, my guess is an Aussie truck.
