Trailer challenge

[David_Hayward (RIP)]

I know that the E987T [short wheelbase] and E917T were available to British forces but the body looks to me like the wooden Searchlight body for the South African Defence Force on the E917T chassis. I conject that this is a South African truck in North Africa, formerly a Searchlight truck with same removed as by then they were obsolete. I have a photo of 1940 Model GMC S/L trucks about to be renovated and used as G/S trucks etc. in the UK in late 1941. Could those markings be South African?