Hi Liz,
It would be good if the John Cain who was with the Dukes turned out to be the same one who was with his maternal grandparents Hugh Cain & Esther Kissack - and that he was your John Cain - because that would give you another two generations going back. I couldn't find Hugh & Esther after 1861, only Jane (wrong age to be daur Jane, mother of John), and John, with the Dukes.

A William Duke married a Jane Cain 25 June 1842 Braddan, which is why I wondered whether she was related to Hugh Cain, and took in his grandson John after 1861.

I don't have a Braddan map. Is Cronkbourne Village anywhere near Union Mills? Or Camlork?

Sue