I'm glad to see the mentioning of Oglethorpe's Highland Independent Company of Darien....I used to be in reenacting unit that did this unit, as I lived only 15 min south of Darien Ga. The uniform was "a kilt of non discript tartan, with another non disticript tartan for matching hose and jacket" SO almost exactly as the wealthier Jacobite's of the time (1736-1746) would have been wearing...only here in the colonies!
As far as after that, I would say that it would have been more likely to have been saved for weddings and such.
Cheers,
Chad