What a bottler of a badge! I am quite envious. The SH was, as you say, initially raised mostly in Natal from keen Scotsmen or chaps of Scottish descent. As Stirling says, took the field in 2/01. More lads came from the Highland Society of London and the Highland Society in Melbourne provided some hundreds for the 2nd. BN. If it interests you, I will post a pic of a more simple ScH brass title.
Roy - Amazing coincidence.
Earlier this PM I was digging thru some old photos left behind when I sold my previous ABW Collection. I came upon a cabinet card photo of a Scottish Horse Trooper with his wife and two children taken in Dundee. His slouch hat is on a small table beside the group and the SH badge shows overlaid on a dark fabric rectangle. While not very clear, with a glass you can see it is the same badgeyou posted. He has the period cartridge belt over his shoulder. I recall buying the photo in Carnoustie, just up the road from Dundee at Stan Pagets home years ago.
If I can get a clear scan I will post tomorrow as time permits.