John Shea/O'Shea

I am looking to find my Grandfathers family. His name was John Shea or O'Shea he was born in 1862/3 in Cahersiveen. He joined the army as a young boy and I am guessing that he must have served for few years as I can't find any trace of him, until he married my Grandmother Susan Rae in Glasgow 1901. Where he states that his parents were John O'Shea and Ellen Lynch both deceased. He died in Glasgow in 1939. He spoke of having a sister who went to America name of Mary or Margaret, No date. They had 7 Children that survived, names are Mary, Patrick, John, Henry Flood, (my father) Nora Lynch, Michael and Cornelious..  I am hoping that someone has a story that could be his family..