Scott,

Thanks for the reply.

So if I understand correctly, using my own affiliations as diagrammed in my opening post as an example, the principle affiliation falls primarily along paternal lines where possible. Thus, if my great grandfather (the Buchanan) were not such, his marriage to an Aberdeen allegiance would bring him and his descendents under that fold, regardless (at this point) of what was present in the Ellis & Lyons side of the family (my father's maternal predecessors).

If neither the Buchanan nor Aberdeen allegiances were present (in my fathers paternal ancestry), in the absence of a legitimate tartan allegiance in the Ellis branch, the Lyons affiliation would be claimed/passed down.

Is that correct?