Thanks for the explanation, Raymond.
Evan Christian b.IoM, Tailor? and aged 41 in the 1861 census, could indeed be Maughold Evan. Wife Margaret was only 26, son Evan 12 b.Liverpool, Lancs, so they may have married in the late 1840s in Lancs?
Their marriage cert would give you Evan's father's name and occupation which could confirm who he was.

Free BMD index has a marriage for Evan Christian and Margaret REILLY June Quarter 1860, District Liverpool, Vol 8b, Page 507.
You can order the cert online. If you look at the final paragraph in this board posting it gives a very good account of how to do this:
http://www.isle-of-man.com/cgi-bin/interests/genealogy/bulletin/index.pl?noframes;read=519450

Because of the marriage date it looks as though Evan aged 12 in 1861 was Evan's son by a first marriage, unless he was born several years before they married.

Now I see where that birth year for Evan of 1810 came from! The 1851 census has an Evan Christian aged 1 b.Liverpool with father Evan aged 41, ?Carrier, wife Elizabeth 42, both b. IoM, and several children b.Liverpool. The eldest son William is aged 17 so their marriage would have been pre-civil registration if in England, and his father Evan most unlikely to have been b.1820.
So were there two Evan Christians b.1849/50 Liverpool, sons of Evan Christian b.IoM?

I'd buy the marriage cert copy to see whether that gets you further, unless the Lancs researchers have better suggestions?

Sue