McMahens in Armagh

[debrao]

My ancestor William Moore McMahen born about 1811 in Armagh ,possibly the son of James McMahen and Ann Moore.  According to an Australian Encyclopaedia article, William, and most likely his parents, came to Australia in 1820 although I can find no record of it.

William married Margaret Keys from the Keys family of Tyrone in Melbourne in 1846 (in the Presbyterian Church) and died in Melbourne in 1892.

I am looking for records of William's birth and emigration to Australia as well as any records of his parents or any brothers or sisters or extended family in Ireland.

Can anyone help me?

[debrao]

I should add that having obtained a copy of William's death certificate it seems more likely that he came to Victoria around 1840 rather than 1820. It also seems likely that James and Ann were his parents.