I had tried to imagine what your revelation about Hirst would be, but it still came as a complete surprise! Yet another amazing story revealed by medals from the Boer War! Since I usually like the stories of the men more than their medals, I would still pay as much for Hirst's QSA, and then add a bit more for the KSA. Do you have anything on Hirst's post-war life? Presumably, he never saw either the ILI casualty roll or the memorial.
I have not checked, but I suppose there might have been ILI men listed as 'missing' after the Battle of Spioenkop, one of whom was misidentified as Hirst.