It's just been pointed out to me that the RGA had mounted troops, drivers, but nobody's suggested them or ruled them out. So could there be an RGA connection ?
And just to reiterate the main question from the first two posts, which hasn't yet addressed,
"I'm specifically wondering how much it is possible to tell [about the mounted chap] simply from his uniform and equipment."
and
"The sort of things I'm wondering include:
Is it possible to tell whether it's the Boer War, WWI, post WWI, or one of the other conflicts around that time period?
Is it possible to tell whether he's cavalry, artillery (driver), mounted infantry, or yeomanry ( I believe, possibly incorrectly, that the yeomanry was the mounted arm of the volunteer force, which became the TA)?"