Good to hear that you are aware the errors. Many still are not.
I believe Isaac died in Hartford, Connecticut since that was the lead in for the obit which appeared in a Syracuse, New York newspaper. It says he retired in 1886 because of the eyesight problem.
You might try searching around to see if his papers were donated to a library or society or Union College, Schenectady NY where he graduated. I'd start with Connecticut and New York.