I think that you should get some useful info via some of the rabble on the jacket and accoutrements but the tartan is more difficult and something that's never been tied down with any certainty. A fact not helped by the lack of contemporary specimens, accurate portraiture or surviving regimental records.

It seems certain that the original dress was the feileadh mor and most writers follow Stewart of Garth's view that the current Government sett was designed at the time that the Independent companies were regimented in 1739 but elsewhere Garth talks about a red line being included at the behest of Col Murray. Irrespective of the actual sett; Government or Government plus red line (i.e. Murray), the shades at the time would not have been as dark as those used by the military since about 1880 and still seen today in the RRS’s version – Government 1A.