Thanks much for that informed comment. I hopeyou can find time to complete the paper, and I hope you will let others know (particularly me!) when and how it is available.
Here are some related bits (distantly related, but maybe of interest). I've spent a lot of time on the Condra/Condrys from Tennessee who, according to both family story and public record, intermarried with Cherokee Indians during and after the Revolution. As you may know, many of the early traders with the Cherokee were Scots, who produced some of the old Cherokee families listed in Emmett Starr's history (names like Bushyhead, from the highly visible red hair). It's pretty common in the literature, such as it is, to find these mixed-bloods described as having dark complexions, red hair, and green eyes--that's apparently characteristic of a Celtic-Cherokee mix.
Another common name among those groups is Looney (some may remember the legendary Oklahoma football player named Joe Don Looney, who aborted his pro career and went off to India to groom elephants under tutelage of his guru). The surname Looney apparently derives from Lleweni, said also to be a Manx name.
I have in my files a number of records of Condrys with Tennessee origins (Grainger and Claiborne Counties) who served in Confederate units in Tennessee and Arkansas whose physical description is virtually identical--about 5 ft 10 in, dark complexion, auburn hair, hazel eyes. One of them served in the 1st Cherokee Cavalry in 1863, when he was discharged because of an ulcerated leg that refused to heal.
I know this physical description alone cannot confirm Celtic origins for these guys, but I find it interesting, first, that such descriptions exist, and second, that they are at least compatible with other descriptions of people with indisputable Celtic origins.
In your researches, by the way, did you happen upon anything that would confirm or refute the claim that Lleweni is a Manx name?