This must be my lucky day.I have just replied to a message posted on Ancestry from a descendant of Martin Jr.
I am descended from the daughter, Margaret, who married John Ker.The son, John Deady, was first to leave Ireland, in 1831, and settled in Ohio, near Cleveland.I have been in contact with 1 of his descendants for many years, and my grandmother's family was very close to them.
Martin Sr and the rest of the children left Ireland in 1838 and quickly settled in Streetsville, Ontario.
I have pretty much the entire family tree - up to several generations - for both the Canada and USA folks.
Would love to hear from you.I can prepare and send GEDCOM files which are small enough to get through email.