Lá Fhéile Phádraig Sona Daoibh
I got this post yesterday - I'm sorry I hadn't seen this thread until now.
My branch of the clan came from Tullycreen, Co. Clare. I'm not sure if this helps, but my GGG grandfather was John O'Gorman (1765-1851) who had two wives. With his first wife (Johanna McGuire) he had a daughter Margaret (Married Patrick Howard) who remained in Ireland and whose descendents were said to still be farming in the area in 1918 - so you may find some connection there.
My GG grandfather was also named John (1798-1884) and he immigrated to Canada in 1829, while his father John (b.1765)moved to Canada with his second wife (Mary Foley) in 1835. My G grandfather was John Keaton O'Gorman, my grandfather George (1885-1967) and my father David (b.1925).
Another descendent has put up a site with O'Gorman family information that was gathered in the early 20th century by Father John R. O'Gorman, and includes information about descendents in Ireland, Canada, the U.S. and Australia which may be of help to you.http://www.isellorillia.com/ogorman/pages/familytree.html