Averil, the Maughold burial register has James LOONEY buried Jan 10 1770 [not John]. No age given.

John Looney Maughold burials were:
Jon LOONEY May 21 1728
Jon LOONEY (a child) Sep 15 1741
John LOONEY Jul 28 1769
[to 1770].

There were also burials:
Jon LOWNY Nov 14 1699
Jon LOWNY Jun 10 1700

It is usual to work from the present backwards, rather than from an early ancestor forwards. How do you know that one of the two bapts you are looking at is the correct person?
Who is the earliest Looney/Lowny you are certain about after following back from bdms, wills, etc?

Sue