All your information matches mine.My Aunt visited Dunlap Ill right after their home was torn down.She has the newspaper articles about it. I believe John Sr and Smith were brothers. My John was born in 1795. There is a picture of his grave stone on Ancestry.com in Peoria, Ill. Died in 1866.
I guess John Jr. and my great-great grampa were brothers, William Emmett Dunlap.