The number of John Doyle individuals, born in Ireland, with Margaret as a spouse is beyond imagine. As a suggestion, I would recommend that you begin with yourself, if you haven't already, then with your parents, your grandparents, your great grandparents, etc., all in that particular line, obtaining their birthdates, and places. This should help you narrow the possible dates and places of birth. Use census records, especially after 1850. If their children were still alive in 1880, pay particular attention to the birthplace of their parents. Good luck!