Hello Julia, I assume you mean the Garda or police force here in Ireland and not the military in the British Army, regiment known as the Irish Guards, there is a Garda Museum here and I found them helpful previously, https://www.garda.ie/en/About-Us/Our-History/The-Garda-Museum-at-Dublin-... Send an email and hope.
I see a wrong marriage here but the name is unusual so may mean something, father is wrong but the Christian name is a bit unusual so may mean something to you. Also only this mans father death is online on Irish Genealogy https://www.irishgenealogy.ie/en/ The death records only go to 1970 so he may have died later but he does not appear to have married before 1941 either. This site is free but sign in etc