My great-grandfather was Patrick Joseph Manley born 1841 in Ballina. He was taken to England during the famines by his father John Manley (1791-1871) and Dominick Manley (1804-1885). I have the death certificates for both of them and have located John's grave. It sounds like your line left after this time. I have gone through the LDS microfilm for Co Mayo and located three John Manleys in the 1856 Griffith's valuation. I can share what I have. I have also been in touch with a couple of other Manley's from Ballina.
I am looking for the descendents of Vincent Manley born 1873 'Vin' who went to Ontario, Canada