Thank you Donna for providing his military papers but not much help as his signature is a bit shaky to decipher it.
How about the ancestors church marriage record? What spelling is on that document? What notation is on 1930 and 1940 census? Since he lived pass 1940 and if still not naturalized than an Alien Registration Form he would most likely had to fill out.
take a listen to all the spellings of the surname you found http://ivona.com
if anything else you hear.