Hi,
I am also researching a Hiram N. Scovill/Scoville, for a friend. I was lead to Hiram from a marriage certificate from his son, William Randolf Scoville of Fulton, NY. On the certificate, William lists his parents as Hiram N. Scoville and Elizabeth Newton. William was born in Granby, NY (as per what is listed on the certificate). I have had a lot of problems finding the Scoville's in the census records. William was born sometime in 1880/1881.
When trying to find Hiram N. Scoville, I found one in Ohio, which is the information you have. But I also found Hiram in 1870 Census in Granby, NY (Sheet 85), living (17 years old) with his father and mother, Ezra and Nancy Scoville. Siblings included: John, George, James T, William B, and Cora B. Ezra was a traveling minister. He is listed in the "A Survey of the Scovils or Scovills in England & America... 700 year history"
Since I live about an hour away from Granby, NY, I will be going up there sometime in the next month to see if I can find any records on Hiram or Ezra. Since I have very little information (official) linking everyone together, it is possible that these Hiram's are one in the same. Here is my email address: yellow_maple01@hotmail.com. I would be happy to share any information I find with you. I hope I can find out information that will help you!
Good Luck!
Rebecca Forbes