Sadly, Deana, just about everything I know is from research, too.Your Nathaniel III was half brother to my third great grandfather, Daniel. Nathaniel II was married to Sarah Bird, Daniel's mom. From what I can tell she died when Daniel was still a baby, and then Nathaniel II married Mary Faunce, your direct ancestor. A variety of Marbles (some brothers, cousin, in-laws) moved into early Geauga County, OH (later Lake County), Daniel moved, too in early 1824. While others then moved on westward, Daniel and his family stayed in Kirtland.
I do have some deeds and am going tomorrow to the local FHL to rent another film from Ontario, County, NY which has what I believe is a copy of the deed for Nathaniel's (I) land in NY.
Nathaniel and Abigail's oldest child Aretas was only 17 when he died in the early days of the Revolution (still don't know where). My maternal grandmother told me that we had an ancestor who was a 17 year old school teacher; he gave up teaching to join the Revolution. My uncle has the earthenware ink pot that belonged to this 17 year old. I still can't prove that it belonged to Aretas, but he is the only 17 year Rev. soldier I've found. From what I've read, Nathaniel had a penchant for donating land for schools.
Feel free to email me, and I can give you more extensive information. Also, if you would like copies of the deeds and also Nathaniel II's War of 1812 military papers, I'll be happy to send them. (He was only in service for only 9 days.)