There are simply too many Thomas Cain(e)s born around 1850--about 16 ch 1848-1852. I can eliminate some of them who stayed on the island. The naming of the children didn't follow the old Manx patterns, so that doesn't help either.
Perhaps some of the info from Canada will help to narrow it down. In US, the immigrants were naturalized and those papers often have good info--don't know process in Canada. Obituaries, local histories, etc often contain background info.
Let me know if you find out more info.
Donna