I'm a descendent of Arthur and Margaret (Alexander) McCann's son Bernard. I have Arthur as born 1801 but I expect he's the same.
I have ample information on Bernard's descendents, and a bit of info on descendants of John, another of Arthur and Margaret's children (there's another living McCann, Bernie McCann, in Harvey, York County, New Brunswick, and he is from John's line of the McCanns).
Arthur and Margaret settled in Harvey, New Brunswick. I have a picture of their gravemarker which I can send you if you like.
Where did you get the info on where they'd come from, and on what ships?