I am an O'Grady also who is very frustrated not being able to trace how my ggrandfather arrived in Australia. His name was Thomas, father Michael, mother unknown (as listed on marriage/death certificate extracts). My grandfather was Frederick John Francis, my father was Frederick Thomas John & my Uncle Francis John Leo. Thomas lived in Paddington all his life & married Annie Agnes Slattery in 1882. I am gambling that you may have useful information to share.
Regards, Pat (O'Grady) Bedford