Jim, the problem is that there are four William Skillicorns in Douglas/Braddan aged 4 & 2 in the 1841 census, any of whom could be your William (and there may be others as well, e.g. the 2-yr-old in Ramsey). Please see Brian Lawson's index (plus other years) at:
www.iomfhs.im/lawsons/LawsonBMD/census/1841-census/c41-s.html
1841:
SKILLICORN William 4 Braddan 1463/5 22 5
SKILLICORN William 4 Douglas 1465/7 17 30
SKILLICORN William 2 Douglas 1465/3 44 21
SKILLICORN William 2 Douglas 1465/5 23 41
SKILLICORN William 2 Ramsey 1464/8 44 19

I wouldn't like to hazard a guess as to which one is the most likely, so you really need the marriage details to find his father's name and occupation.

Sue