Without a service file, it really would not have been possible to correct anything. He would have needed the signatures and statements of two veterans to verify that he actually served as stated. Many veterans did exactly that.
After looking in several places, I don't find a service file for him, either. Jasper Conway did repond to the 1907 census for Confederate veterans. He gave his birthplace as Girard, Russell County AL, Oct. 24, 1847.