I came across an old book in the local Oxfam store and bout it for £3.50. (Just found it on ebay for £99.00) It's called 'The Kilt and How to Wear it - The Honourable S. R. Erskine - 1901'
It's really a book of it's time filled with advice not to wear loud, unflattering clan tartans and to just pick a nice quiet one to wear for your rambles in your new Scottish manorhouse.

Flicking through the pages I came across this wonderful gem. (Which could really keep Dreadbelly in business.)

The bonnet is an important article of the Highland dress, because it gives a certain character to the whole. Moreover, a man's head is the most striking feature of his anatomy, and it is essential that it should be suitably covered.
There are at present in vogue in Celtic Scotland two kinds of bonnet - The old flat bonnet, which is sometimes, absurdly enough, styled the Balmoral; and the semi-conical "Glengarry."