Speaking from my own experience as an historical re-enactor. I belonged to a highland regiment Fraser's 78th Highlanders of Foot of the French and Indian war
or for our friends across the pond, the Seven Years War. We wore the great kilt as our uniform.
And being the only regular British troops out on the field we had to look sharp. what we did was to sew three loops along one edge of the cloth and after it was pleated in the normal fashion, we put the kilt on and prceed to tuck the bulk of the material into our belts to form a triangular shape then we took all of the loops and attached them to a button that was sewn just below the left shoulder or on top of the shoulder.This helps take off some of the weight of all the extra material and also is a conveniant way to carry extra gear like black powder charges that are need for the battle re-enactments.Or non-period water bottles that had to be out of sight.
I think that the paintings are of the 42nd Highlanders of Foot also known as The Blackwatch.
I hope that this is helpful.There is a web site for Fort Ticonderoga that shows photos of some of the highland units.http://www.fort-ticonderoga.org