The 1880 U.S. Census for Monroe, Monroe Co., MO, p. 578C:
Josiah C. KANE, self, m. male, w. 40 Ohio wagon maker Mary KANE, wife m. female w. 40 Indiana keeps house Harvey KANE, son, s. male w. 13 Indiana John KANE, son, s. male w. 8, Missouri Martha KANE, daughter, s. female, w. 6 Missouri Emily ROBINSON other s. female w. 17 Missouri servant
Mary KANE lists father's birthplace as New York, mother's birthplace as Ohio.No listing for Josiah's parents.
According to oral history, Harvey KANE married Martha SHACKLEFORD and they had a son, Clifford Harvey KANE, who was born in Florida, Missouri (don't know exact date).Clifford Harvey KANE married Maude Lorraine BURBRIDGE c. 1907 and they lived in Hannibal, Missouri.They had 7 children.
At some point in time, Martha SHACKLEFORD divorced Harvey KANE and married his brother, John KANE.They had a son, Merritt KANE.This is probably the Donald Merritt KANE who was your grandfather.So, according to the information I have, John KANE, son of Josiah and Mary Doolittle Penrod Kane, would be your ancestor.
I haven't been able to prove this oral history yet, but am working on it.Perhaps your grandmother can help and I would very interested in any documentation you have.