there is a bit about John Jame in A W Moore's old manx families www.manxnotebook.com/famhist/families/awm1889/chrstn_p.htm
John James was almost certainly in the running trade (smuggling) as post 1765 the merchants based on IoM had to find other places from which to run goods and before the French revolution Dunkirk and other places along that coast were used.