I've got Scarlett's booklet about military tartans. He discusses some of his interesting theories concerning the development of the Government tartan - don't know if they'll ever be more than theories, but interesting!

The booklet also contains useful color illustrations of the tartans discussed, especially of the musicians' tartans and of the theoretical "missing" tartan from which he claims the Government tartan evolved. He also takes the "42nd Kilts" (blue/black/green superimposed blocks with red strips in the blue and green squares) back to the mid-18th c - again, based on what Luke has said about it, I don't know if that can be proven.

I have modern box-pleat kilts in "42nd Kilts" and "42nd Band" (both thanks to Peter) and they always garner compliments when I wear them. Historic tartans are something for clanless/unaffiliated individuals to think about, rather than the limited number of universal tartans out there. Scarlett's booklet and Peter's research papers are what got me started on that.