Early 1800's search

I have searched Ancestry, Roots Ireland, Find My Past and Family Search (LDS).

I am not sure that my GGG Grandfather, PATRICK FLANAGAN, is from Roscommon - I only know that he was from Ireland. However, in searching the above sites, I have located a Patrick Flanagan that I'd like to look into further. Date of Baptism - 22 Feb 1820 inTibohine(per family search). Roots Ireland lists the parish asLoughlynn. Parents: Michael Flanagan and Catherine Downs. There is also a Michael Flanagan listed - DOB - 1 Dec 1822, same parents. Both Patrick and Michael have sponsors named DOWNS and CONAUGHTON.

The Patrick Flanagan I'm looking for was married in Boston, MA in 1845, and based on census records in the US, a DOB of 1820 seems reasonable. Two of his children are named Catherine and Michael (my GG Grandfather), so the parent names on the Baptismal certificates seem a good fit.

Thank you in advance for any assistance. I plan to visit Roscommon in the summer to look into the original documents.