Hello Dave,
Yes, they were worn during the war, so many could be found in South Africa simply because the whole Army served there, the 6th DG looks as though it's seen better days, the 6th D, is very typical of what you can find out there, but, because it was worn beyond the war unchanged, other than the fittings, of course, they are rather more common, looking at this latter, from your photograph, your example is one of them, those worn in South Africa during the war had two copper loops.
Both these were worn on the FSC and then on the Slouch Hat, both were very good regiments in Tom Porter's brigade, you know, I honestly believe he was perhaps a little under rated as a cavalry commander, he looked the part too, there were rather few really good ones in the nineteenth century, but, he really was absolutely "up there" and every bit as good as the likes of Stapleton Cotton and Henry Paget.
Regards Frank