Arcadia on Family Tree Circles

Abel, or Abraham is my brick wall. I have been researching him for approx 6 years now. What makes this particularly difficult is there are 2 Abel McDonald's living in the Cayuga area at the same time, with sons named Abel. They were both born within 3 years of each other, in Upper Canada. One was married to Matilda ?? about 1847, with a son named Abel born 1866. This one is my gr,gr,gr grandfather. (It shows on Abel Jr's marriage registration father's name Abel, mother's name Matilda. He married Minnie Harcourt.
The other Abel married Ann Jane Hull and also had a son named Abel.
I have been unable to find any information whatsoever on Abel McDonald Sr, who his parents were, if he had any siblings.
I have Abel and Matilda in the 1871 Census in Kent County.
Any help would be greatly appreciated.
thanks,
Gerri