Below is an extract from Brian Lawson's IOM census indexes, showing that there were only 3 very young children named James Wade in 1841:

www.iomfhs.im/lawsons/LawsonBMD/Main_Site_index.html

1841 IOM

WADE James 15 Bride 1463/6 30 5
WADE James 12 Jurby 1463/9 27 9
WADE James 5 Andreas 1463/1 57 11
WADE James 5 German 1463/7 21 7
WADE James 2 Lezayre 1464/1 49 18
WADE Jane 70 Ballaugh 1463/4 39 1

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I've looked at the relevant census pages and:

The 2 yr old is the "wrong" one (son of John and Elizabeth)
The 5 yr old in German is a son of Thomas and Ann.
The 5 yr old in Lezayre is a son of John and Dinah.

So there was no small boy James Wade with a father, William, on the island in 1841. If he was born on the island, the family must have left soon afterwards, and his baptism isn't in the IGI. Also, if he was born on the island, we can't discount this possibility: that James was the biological son of Mr X (legitimate or illegitimate) and James's mother subsequently married William Wade who gave his surname to James.

The most likely scenario is that James wasn't born on the IOM, but his father, William, was.

Do you know when James died, and his age at death ?

I wonder if William Wade was a soldier (living in Castletown, Malew) who left the IOM with his regiment between 1839 and 1841. Does anyone know about the movements of regiments around this time ?

Another thought ---- are there any unusual middle names of your father's generation of Wades ?

Jean C