In reviewing "The Little Gods: Union Provost Marshals in Missouri 1861-1865" Eakins and Curtis, 2002
it appears that Issac Snedecor in official reports always spelled brother James Parker Snedecor as Snedicore. This is how Maj Harman first spelled the name. The only place I find where Issac spelled JP as Snedecor was a private letter to Dr James Martin in St. Louis. I can't believe folks in Fulton did not know of the relation but those in command may not have.

FWIW.