Looking rather the worse for wear again, these photos of the memorial were taken on June 7th this year.
I'm inclined to think that it wasn't originally intended to be a Boer War-specific memorial. Corporal Wilson Wiles is buried there so it's his memorial/headstone (there's another member of the Wiles family remembered on the side of the base) and the names of Hardy, Wilkinson and Outhwaite were added after the war ended with the Wiles family's permission; they are, presumably, buried in South Africa. Just my opinion.