one is the Parish register for st marks that can be found on a search for John Cubbon death in 1799 in the lds site familysearch.org, another in the will of one of his inlaws - forget which off the top of my head, either Robert Crellin (d.1780) or his wife Margery Comish (d. 1768) and the third I'm not sure where to point to but was a list of Manx nicknames. As I write this I'm wondering if the modern rendering shouldn't be "Disty"(?)