What was the place of birth given for him in the 1860 census? Does this census give any information about date of arrival in the USA? Did you check the other censuses for his wife to see whether she was a widow?
If he was in the census as Henry or Harry, where was he recorded as William Henry? You need to give all the details you know.

The IGI has submitted entries (unreliable) for a WILLIAM HENRY CORLETT Christening: 18 JUL 1829 Lezayre Father: WILLIAM CORLETT Mother: CATH KNEALE, which may or may not replace the original parish register entry, and other submitted ones for b.1835, plus one 1835 extracted (from par reg) William Henry in Andreas. There are many William Corlett entries.

This is why you need to find out everything available recorded during his life in the USA (passenger arrival, marriage, death, MI?) to know who you are looking for in the IOM.

Sue