With my interest in the Elandslaagte clasp, my brother and I were fortunate in being able to collect the clasp to many of the units present but the Carbineers remains on the todo list for me and has been there for many years now.
As with you and Chris, a Carbineers' QSA with an Elandslaagte clasp has eluded me. Unlike you, my Carbineers' collection covers the period from the Zulu War to World War II, so that single absentee is all the more galling. I suspect that Rory knows this and is keeping his example well hidden.
I was told that recently another example of this medal was sold by Spink for a very low price. The seller missed a great opportunity by not offering it to me. Apart from a far higher price for the medal, he would have saved on postage to the UK and Spink's commission.