John
A little more about the locally raised mounted troops and their headwear in early to mid 1900.
An amusing anecdote concerning battlefield confusion in the aftermath of the action at Belmont may be found on p.33 of that excellent work "With Rimington" by L. March Phillips. Rimington's Guides and March Phillips were involved in recapturing a herd of cattle (lately in Boer hands) and conveying them to the rear:
" From a group of Staff officers, a boy came across the veldt to me and presently I heard, as I was shooing on my bullocks, a very dejected voice explain 'How confoundedly disappointing'. I looked around and saw a lad gazing ruefully at me, with a new revolver tied to a bright yellow lanyard ready in his hand. 'I thought you were a Boer' he said 'and I was going to shoot you. I've got leave to shoot you ' he added as though he was in two minds about doing the job anyway ........ and then, still ruefully, he rode away. This was right up our end of the valley and I was driving the cattle onto our ground, ONLY I HAD A SOFT HAT ON" (my emphasis).
Perhaps it was due to incidents such as the above that RGs adopted the leopard skin hat bands as a quick ID?
More evidence regarding the official avoidance of wearing confusing headgear may be found on the website of the ANZAC Memorial (Sydney, NSW). It tells us that the 1st NSWMR arrived in SA wearing slouch hats - but in Jan/Feb 1900, the Field Force Commanders decided they may be mistaken for Boers and they were reissued with FS helmets. There is a well known sketch by Norman Harvey showing 1NSWMR in action at the Vet River (5/5/1900) wearing FS helmets with a large stylised A on the LHS of their headgear.
I realise that the above is seemingly a bit removed from the thrust of your initial query about the uniforms of Robert's Horse. However, it appears that the wearing of FS helmets by many locally recruited and oversea Colonial mounted units was rather widespread in the formal stages of the SA Campaign.
Regards
IL.