Its an interesting question about how far you go to be "authentic". My name is Baxter. We are supposedly a "sept" of the MacMillan clan, and I have an ancient hunting MacMillan kilt. I have been tracing my family history, I have managed to get back to the early 1500's in a direct paternal line. Where an I from? the east coast, Fife and Dundee. Not a connect with the west coast MacMillans. So should I wear the Baxter tartan from the Fife Baxters? My GGGGG Grandfather moved away from Fife and into Lanarkshire in the early/mid 1700's. So, is 250 years since I had a connection with the Baxter's from Fife.

From the tartan genealogy web sites I can wear the following: (all only from my paternal great, great grand etc grand mothers. i have not even looked at my maternal side yet)
Currie = Macdonald and or Macpherson tartan. Ballantyne = Bannatyne = Campbell or Stewart of Bute tartan. Grewar = Drummond, Fraser or Macgregor tartan.

Quite a selection and all pretty meaningless to me in the here and now. When I get a new kilt, I'll just pick a tartan that I like, or I'll design my own. So, Offline, if I were you, that's what I'd do.