Welcome from California

I am in a somewhat similar situation. There were precursors to the name McElmurry in Lewis, Harris, Ulster and the Isle of Mann. I will likely never be able to trace my McElmurrys back to their original lands. I will probably join Clan Morrison and wear their tartan and perhaps wear Ulster in recognition of my Scots-Irish ancestors and the possibility McElmurry originated in Ulster.

So, I have decided it is appropriate for me to recognize both my Scottish and Ulster heritage and that the two are not incompatible. You have to decide what makes sense for you.