Hello Eddie,
It sounds fascinating that your Grandfather was a politician here on the island of Ireland in 1923!
We have several articles and a wonderful community post on
Tracing your Irish Ancestors by our friend Brian, which has lots of helpful starting points for your research journey. As he suggests, the 1901 and 1911 census returns may hold some clues and help establish places and dates that you can then use to further your search.
Have you any paper documents handed down through your family that may shed some light on his past before becoming a member of Dáil Éireann?
Martin