Looking for Stafford Before Lepreau

I am researching the Staffords that came from Ireland to New Brunswick, Canada in 1830. At least that is the date of arrival noted on the earliest census return. My Staffords are Robert and Elizabeth who might have a connection to Tullynacross, Ireland. I do not have a ship name or any clue as to the rest of the family in Ireland. The Tullynacross connection is from an obit published in the St Andrews Standard(a New Brunswick paper)in 1840 for a gentleman named Robert Stafford from that town. I am hooping that there might be a clue somewhere in the local records as to the town in Ireland that they came from. I have all the on line info from census and provincial archives.