Is anyone still looking for information on these people? I do have some information but not sure of exactly how accurate it is. As others have, I have experienced major headaches and have had to put the research away for a bit and go back to it several times over, as I seem to go in circles. William Milloy (b1828) is my great great grandfather through my direct paternal line. That much I do know for sure, and the people between he and I on my tree. There were marriages and name changes that confuse things, but I have documentation of his father being Dugald/Dougald Milloy, who was born in Saddell and Skipness, Campbelltown around 1796. I also have documentation of Dugald's father being Iver Milloy.
Dugald's daughter Margaret Milloy was baptised in Saddell & Skipness in June 1827. Her brother William was born in Ireland. I am not sure of much in the Ireland part of things, but I recollect coming across Downpatrick at some point, perhaps not in direct relation. I have a possible spouse Catherine Macgregor at some point, and other possible siblings Alexander and iver. Dugald returned to Scotland to Oban to live out his days as far as I can tell.
Back to Margaret, I have a record of Margaret Monagan [Margaret Milloy], daughter of Dugald Milloy who, as a widow, married James Smith in Belfast, June 1852 at age 34 years old, putting her birth around 1818.
Is this helpful to anyone still? Are there people still following this pathway? I have a few more details, but this is basically what I have cobbled together in over 10 years.