Guckian/Geoghegan Lineage (Leitrim to Westmeath)

Hello,

My name is Chris Guckian, I live in West Palm Beach, FL and have been trying to understand my heritage for as long as I can remember. I will be in Ireland in May and am very motivated to discover as much as I can about the lives of my ancestors. I have collected everything I can find from various sources online, no-one in my immediate family had any information outside of stories from my grandfather and great grandmother who were both born in the US.

My great grandfather Michael Guckian (1898), immigrated to NY in May 1921, 2 months after the Ambush of Sheemore. He was the son of Patrick Guckian (1859) and Eliza (Flynn) Guckian of Correen under the Carrick-on-Shannon court. Their 7 children from oldest to youngest:

John (1891) - Immigrated to Philadelphia, PA, USA

Francis (1892) - Immigrated to Brooklyn, NY, USA

Patrick (1896) - Immigrated to Brooklyn, NY, USA

Eliza (1897) - Remained in Ireland

Michael (1899) - Immigrated to Brooklyn, NY, USA

Thomas (1900) - Remained in Ireland

James (1902) - Remained in Ireland

I am fairly confident with this information compiled mainly using the 1901/1911 Census as well as my great grandfathers obituary. 

I believe Patrick’s father was Francis Guckian (~1820) as stated on the marriage license to George Flynn's daughter Elizabeth with John Guckian as a witness. I don't have much else from there, but if I turn to the petty sessions where he is heavily featured along with a Thomas and Joseph Guckian on a number of occasions. There is one incident in 1850 that puts Thomas Guckian Sr, Alice Guckian, Thomas Guckian Jr and Francis Guckian in the same house. 

This is the basic understanding I have acquired over the years, I wouldn't be surprised to have taken a few missteps and the story needs correction but this is the best I have so far. Any help would be greatly appreciated