James,
I'd follow Rich's advice and get a copy of John McCleod's "History of Royal Dornoch" if you can.
Looking at my copy, there are plans of the course as it was in 1892 and 1906, as well as the current layout dating from 1948.
Tom is pretty much spot on with his memory of the layout and changes in from the 1909 to the 1948 layouts (along with Donald Ross changes to 1 and 2 in 1921). The 6th was also a new hole (originally playing to the current 11th green), 7 through 11, plus 13 also being new.
Looking at the 1892 plan, from the plan alone and without greater knowledge, the only hole on the Struie that dates from then for certain is what plays as the 18th on the Struie at present. This was the original 17th, which was followed by another shortish hole of 210yds from left of the previous green to what could be the current putting green? 3, 4 and 17 on the current Struie layout are roughly the same as the 14, 15 and 16 as was in 1892, but its difficult to say?
Hope that helps?
Cheers,
James