How's that going, Eric? Forgive me for not keeping up with the board.
First, my grandfather was your Great Uncle Harold Davison. Next, Nancy Hazen was married to Francis H. Davison about 1839 in Oil Creek PA (documented in Hazen Family genealogy and Jameson Family genealogy books). Francis H. Davison died in 1845, the best I can tell. Nancy's second marriage was to Porter B. Jameson on 23 July 1864 in Jackson County IA. They lived at Cottonville. Mr. Jameson died 4 Feb. 1882. Nancy died in 1910 and was buried in the Mount Hope Cemetery. (I think you already know this, for you took the photograph of their shared grave marker that is online.)
I have located the key people in the 1810 to 1840 censuses. (Francis H. was born in 1816 and orphaned in 1817, BTW. And the legal spelling of his middle name probably was "Halyday", which was his mother's family name. I believe, but can't quite prove, that his maternal grandmother raised him after his mother died.)
I'll be glad to fill in other details for you and Connie offline. Let me know by posting a reply or sending me a direct email response.