Martin gready - Grady

HHello my great grandfather was Martin Gready/Grady.  At the time of his marriage in 1853 in grafton NSW Australia, he said he was from Roscrae.  I am not sure if he was born there and lived somewhere else.... There was a Martin Grady who came to Australia on the Emigrant in 1850 whose parents are listed as Payrick and Ellen.  Are there any records for this family and is there anything regarding him leaving for Australia? My cousin and I are researching our family and have much information to share once we find his origins!

Julie