I would add a bit of caution when asking about a "Carolina" long gun. That term covers a lot of territory.
From what I have learned (I am no expert) there were many different types of guns in the Carolina's. In NC, I would allow that there were three broad areas, like terrain types: Coastal, Piedmont, Mountains.
The Coastal area mainly used imported firearms, often English. Apparently a large number were smoothbores due to hunting waterfowl.
The Piedmont had numerous schools of longrifle making, and many had a strong Moravian or Germanic influence (see Salem, NC).
The mountains were an area to themselves, and this covers the so-called "Mountain Guns". These tended to be simpler than Piedmont guns, but there are always exceptions. Dennis can fill you in on these.
I would suggest buying Bill Ivie's book on NC longrifles. It covers the whole gamut. Dennis' book on the Gillespie's is worth reading for sure. Especially if the mountain guns are your fancy.
The locks in the Ivey book also seem to have no rhyme or reason to why certain guns have certain lock styles. I could be wrong though.
I hope this helps, and I welcome correction if I have mis-stated something above.
Best wishes, Marc