Many thanks, Frances - very helpful.
Still good to have the full transcript on the wills list as well, if Jenny will do this.

It looks as though John Kenish at "Baldooin" in the 1851 census farmer freeholder of 74 acres was this eldest son and heir of Nicholas, as guessed, and was underage in 1784. Probably JOHN KINNISH Christening: 21 FEB 1779 Lonan, Father: NICHOLAS KINNISH [IGI], although he was recorded as older in 1851. Other children possibly: Mary bapt 1771; Ellinor 1776; Joney bapt 1781 (died?) + twin Margaret. Another Joney & Margaret (different months) bapt 1784; Thomas 1778 (this doesn't look right, because John was written first). There were clearly two Nicholas Kinnish fathers having children bapt in Lonan around the same time.
Mother Joney, first marriage to John? KEWLEY - but, being Lonan, the marriages seem to be missing.
In the 1841 Lonan census, at Baldorin, were John Kinnish 65, Catharine 60, Thomas 30, Ann 20 [Jenny, 1841 census had rounded ages, no relationships].

I think Nicholas son of John Kinnish and Alice Crain moved from Braddan to Lonan with his parents - their eldest son William Kinnish bought half the Corony quarterland in Maughold from Will Kirmeene and his wife Jony Cowle in 1695 - and John Kinnish & Alice Crain presumably moved to the Lonan farm, taken over by their younger son Nicholas (d.1734). Alice's 1726 will was in Lonan.

Was Baldhoon/Balldoon in the land records you gathered for Lonan?

Sue