Oh wow! Daniel McLaughlin who married Eliz. Cummings is my gr-gr-uncle! It is his brother Dominick who is the father of my gr-grandfather. Elizabeth's brother David shows up in Scotland in the 1881 census living with Dominick and his wife, which was one of the clues that cemented my conclusion as to who my mystery man was. (Dominick would have been his sister's brother-in-law) There were so many McLaughlins in Northern Ireland back then, likely still are, I suppose. Your grx5 grandfather James may be also an ancestor of mine, as I haven't gotten beyond Dominick's parents names on that line. They would be my grx3 grandparents, John and Jane McLaughlin. Anyway, yes, do watch for my book! Thanks for commenting.
K.