(never seen one in a Victorian depiction).
I'll amend that: The hat is traditional to the Chitral region, and there
is a photo of Chitral ruler Shuja-ul-Mulk where about two out of twenty of his entourage appear to be wearing flat "Chitral topis" but these early examples don't really look like the modern ones: They look more like what we would call berets to me. But I guess that means you could throw a couple in if your game is set in Chitral, and you don't mind that they don't look exactly like the earlier examples.