Thanks again for replies on this subject. Just a wee update, I eventually got the marraige from IFHF and this confirmed they married on 6th march 1872 in St Peters rc cathedral, Sarahs father is John not James Morgan and the Morgans were helpfully mentioned as coming from Ballinderry, Co Antrim.
They lived in Mcdonald St which I assume is no longer existant in Belfast as I cant find it on the maps and this may help others looking for streets encopmpassed by Area no. 4.
I dont understand why roscommon could not find it though it may not have been registerd civilly???
Anyway next daft question, does anyone know what the rc parish in Ballinderry would have been at this time....say 1830-70, do they still exist and would the records exist anywhere?? Thanks again.