I believe that your Robert Gleason is the brother of my great-great-great grandmother, Catherine (Gleason) O'Herron.
That would make Robert the son of James Gleason (b. about 1780 in Ireland, probably County Donegal) and Catherine MacDonald (b about 1790 in Ireland). James died between 1870 and 1880, and Catherine died after 1880. They were born enumerated in the 1870 census, living with son Daniel Gleason in Scipio, and Catherine was still enumerated in this same household in the 1880 census.
They had at least 4 children: - Mary (b. abt 1830, d. 8 Dec 1884, m. Daniel O'Herron/Ahern -- probably was Ahern in Ireland) - Catherine or Katherine (b. abt 1838 in Ireland, d. 24 Feb 1916 in Poplar Ridge, Cayuga, NY, m. Morris or Maurice O'Herron in 1858 in Union Springs, Cayuga, NY. Morris and Daniel O'Herron were brothers, and many of the O'Herron/Gleason children share names, such as Michael, James, Catherine, and Robert) - Daniel (b. 25 Nov 1839 in Ireland, d. 26 Mar 1916 in Scipio, Cayuga, NY, m. Ellen Daly) - Robert, for whom I have birth years ranging from 1841 to 1846, with a death date of 17 June 1888. He is buried in St. Bernard's Old Catholic Cemetery in Scipio).
Catherine Gleason O'Herron was my third-great-grandmother. According to an elderly relative, both Catherine and her husband spoke Gaelic fluently, although none of their children did, and both were illiterate. From this, it is likely that many of her siblings also spoke Gaelic and may or may not have been able to read or write. This becomes important with records, since spellings of their names were entirely at the discretion of whoever was recording the information.
I'd be interested in information you have about your branch of the family. I have a photograph of Catherine Gleason but unfortunately no other family photos from that side.
I also live about 8 miles from Scottsville. If you like, I would be happy to see if I could track down where Mary Flanagan Gleason is buried and take some pictures.