I'll throw my two cents in here if I may.
I too would not wear a tartan I feel I have not earned. Whether it be by blood or other affiliation.
My searches have not turned up any firm clan affiliation. Just a vague line, 250 years removed.
My solution is-- I wear the US Marine Corps Tartan for formal events. For daily wear I have plain kilts. Or, if I feel adventurous, I wear one of the Camoflauge prints I have. During my 20 years, I have worn each of them. In combat. In my mind that is earning enough. That is why I chose to offer the camo prints I do. I also know that to my adopted Canadian neighbours that may seem strange. Even morbid to some.
But darn it, I like kilts. So when someone looks at me in my Desert Storm Camo kilt and ask "What clan is that?" I, in my best imitation of a Scottish burr respond, "It is the HOMSOT clan." They always nod knowingly and move on.
HOMSOT = Halls of Montezuma/Shores of Tripoli