A friend commented to me that a William Corkhill married a Cornish girl in 1775 when he was sailing out of Whitehaven, Cumberland and there were a number of later Corkhills that lived there with him - I was hoping he would add to this and post more info on the board - however this teaser might suggest that you look at Whitehaven marriages etc as many Manx had strong links here in 18th + 19th C.