Thank you, everyone, for your outstanding detective work and amazing suggestions. Obviously, my information that Isaac was born in Tipperary sent me down the wrong track. I haven't had cause to research Irish ancestors before, so you have given me some great info on sources, including BDMs and census records. I guess this is complicated by the partition, if you are unsure which side of the border your people are living on.
I think I'll be able to take it from here. Thanks again, all.
