H of I was the poor house for want of a better term.
Try the Manx Notebook link at the top of this page for a better description.

There is only one Owen Mc Clusky entry in the censuses.
He first shows up in 1861 aged 39 with a wife Bridget. She appears to have died in 1863 aged 35, see my web site.

In 1871 he is 42, a widower, from County Down.

In 1881 he is 48, with a new wife Jane, 47.

Not in 1891 (of course) but Jane appears to be 75 from Armagh.

I have double checked the ages in 1871/81, and that's how they appear in the census. If the 1861 census age is anywhere near correct then he would have been 49/59 in 1871/81 which is close to his age given at death.