Walsh/Paden of Toorymartin and Ardlavagh

My 3rd Great Grandfather James Walsh moved from County Roscommon to New York in the mid 1800s.

In the beginning of my search, I found that there was only one James Walsh in Roscommon records that matched my ancestor's description. James Walsh b. 19 Jan 1819 to Patrick and Mary nee Paden Walsh and baptized in Croghan, Roscommon 11 Nov 1819 with sponsors Thomas Walsh and Elizabeth Flanagan. 

This James has been a good match to date as Ancestry DNA placed me in the North Roscommon community which surrounds the Croghan township perfectly. Many of my genetic cousins have roots in Elphin, and while Paden is not a common name among my matches, Flanagan and Patrick's sister's maiden name Maguire/McGarry is. 

Patrick's page https://irelandxo.com/ireland-xo/history-and-genealogy/ancestor-database/patrick-walsh-0

I recently discovered his family was from Toorymartin and Ardlavagh, not Croghan township which helped immensely in my search. I have this family fairly well documents from a birth/baptism perspective of the children. At one point I even noted that Patrick's parents may be James Walsh and Brigid Ferrall, which in hindsight could make sense because the Farrell family owned the land listed as Patrick's residence in Griffith's evaluation.

Now as more details are coming to light, I realize I have a huge "evidence" gap between James's birth and his new family in America. James married Mary while still in Ireland and their eldest daughter, Bridget, was born there in 1853 according to US census records. US death records matching the details of James's youngest three sons list Mary's maiden name as McGuinness. Still, in Irish records I find no evidence of a Mary McGuinness in the areas James lived, no records of James marrying any Mary nor any birth records for Bridget in 1853. 

My genetic network around Roscommon skews west, so I presumed Mary may have had origins around the Mayo border. Finding the Walsh family's Leitrim border history makes me more skeptical. 

Any insight on this family would be greatly appreciated!