The 78th Fraser Highlanders are recreated today - with chapters in a few Canadian cities. They have a website with photos. The 78th wasn't around by the Revolution. Their big day on the battlefield was at Quebec, in 1759.

As for the 42nd - I believe wore the tartan they have still - the "government" tartan - but I think many ended up in breeches as the kilts wore out and were not replaced.

A "normal" re-enactment uniform from the period runs about $1000 for uniform and $1000 for a Brown Bess. Add a kilt to that - and no worsted wool mind you - the kilts then were hairy like a blanket and well over 20 oz and this will cost you. "Battle weight" means heavy. You need not go that route. Re-enactors are dedicated but of course far older than the real soldiers whose roles they recreate. Young men haven't the time or money for this hobby, usually.

Some people have said my views haven't credibility - but I've seen the Black Watch's tartan from the period in their museum in Perth, Scotland. No question about what it looks like. Good luck.