Did you get a response to your query on James Lang Cairns?
I have a bit of info on the Cairns side. My ex-husbands father,John Angus Smith, is a descendant of James Cairns 1787-1867 and Elizabeth Patterson 1787-1873. I believe it goes - James Lang Cairns father (John Cairns) is a brother to Thomas Cairns, who is my ex-husbands great-great grandfather. I don't have much on the brother, only his name John Cairns 1820-1892 and he married Jane Lang 1830-1925. hope this helps. if you would like more info, feel free to message me. E. Smith