Sorry for the lateness of this reply.
From what I have, it says that Mary Densmore is the wife of Peter McShane, not Patrick. Peter would be Patrick's son. Patrick came to Canada around 1790. I currently work at the Harriet Irving Library in Fredericton, coincidentally enough in the microforms department. So I am in the process of systematically finding his records and perhaps will fond something of use. I will also be making a trip to St. Stephen soon to see what they have there for resources. I will post anything I find on here so everyone can benefit!