Hi There,
I am in the same direct line as you. I don't have anything further back, however our family story was that the family has been in Northern Ireland since 1620's, but originally from Scotland prior to that. The story is that two brothers, who served in the military, were granted land there. When they arrived to start farming they decided that it was not the best farmland and could not support both brothers and their families, so one returned to Scotland and the other remained...who was our ancestor.