Help please Surname Donnelly

Hi,

I am trying to trace my Irish family tree. I don't know much as my father never spoke of his family due to he was married before my mother so because he divorced he was basically shunned. All I know is a few vague facts.

His name was Thomas Joseph Donnelly born in 1935 in Dublin(???). He thinks his aunt was his mum & his mum was his nan!

He left Ireland about 1953 - 1955 & joined the RAF

Thanks in advance

Eddie Donnelly