Your John Dunn apparently is the brother of Asa Dunn, born 1808 and died 1876, who is my husband'ds 4th g-grandfather. Do you have any information on their parents Edward Dunn and Esther ??. According to the census' I have seen, there were about 7 or 8 children one being Perry Dunn who died abt 1824.
Would like to hear from you.