Hi,
I think I can help a little.
John McManus born 9 Sep 1799 in Ardersier married Margaret Murdoch in 1817 in Elgin Scotland. They had at least 11 children, one of which was my gggrandfather John McManus born in 9 Jan 1823.
Looking at the Scotish census records, the family is in Scotland in 1841, but they are nowhere to be seen in 1851 or thereafter. Therefore I believe they immigrated to Ireland because my ggrandmother Geraldine Bridget McManus, born 8 August 1859, testified she was born in Ireland in USA marriage records. Her mother was Elizabeth Flanagan. I haven't been able to detect where in Ireland John and Margaret immigrated to in Ireland, but I believe John and Elizabeth died in Aughindaigh, near Derrylin. FYI, the family, from John born in 1799, etc., were members of the Church of Scotland.