The only Thomas Cooil on the Isle of Man Census was in 1861, but his wife was Catherine. The did not appear on the 1871 Census in the Isle of Man, according to Ancestry:
Cooil, Thomas, Head, Married, age 44, farmer of 43 acres, born in Arbory, IOM
Catherine, wife, 48, farmer's wife.
No children given, but they may have left home by then.
Address Ballabeg, Marown, ref. RG9/4424
I hope this is of some help.
Janet.