Are you sure that the William Corlett who married Ann Cashen in Maughold 26 Nov 1798 was from Lezayre?
Did the 1851 census record this? Or another document?

There was a bapt for William son of John Curlet & Elinor Quayle in Maughold 1 Dec 1765.
Also William son of John Corlett & Joney Cowle bapt Maughold 30 Sep 1774. Private baptism.

Anne dau of John Cashen & Margaret Corteen was bapt Maughold 29 May 1774.

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