Dan,
Thanks for the tip on the Ardfinnan parish records, but I think the Thomastown I'm researching is in the Golden & Athassel parish which is in the Cashel & Emly diocese. Major problem is that this diocese has restricted access to the records and only allows the Tipperary Family History Research Center. The records they hold for this parish don't go back far enough.
I'm not 100% sure about the location of Thomastown, but another researcher has notes from his great-grandmother who claims her ancestors came from Thomastown outside Tipperary. There was a town 1/2 way between Tippeary & Cashel named Thomastown, but is no longer there.
Thanks for the tip and now I know where to go in case I ever need records from Ardfinnan.
Any ideas on where departing ships manifests for abt. 1822 might be kept? I seem to recall hearing that most Irish in the south departed from Waterford or nearby.