Desmond Family Genealogy Forum
Another possible source for his birthdate or at least an approximation, would be the interment listing from the cemetery he's buried in.
The church he was married in would also have an entry which might list his age at the time of marriage.
Here in the city, we're fortunate to have Directories. There might be something like that in the county he resided in. Placing him at a particular residence for a period of time would narrow down the possible churches to search, if you don't have the name yet.
Don't despair Dawn!