What did the "P" stand for?
There was a Patrick Caley aged 20 in the 1841 Maughold census, and a Peter Caley aged 20 in Lezayre.
People often changed their names around after moving overseas.

Patrick Caley was bapt 26 Nov. 1820 Maughold which fits your birth date, because babies were often bapt within a few days of birth.
- Just a suggestion.

Sue