I'm just a hobbyist, Charlie, but until you get expert help here are a couple of suggestions (if you have not already tried them):
Check the county courthouse for possible recorded info. Many WWII vets recorded their discharge info.
If he was wounded, he may have received medical care or compensation from the VA. Do you know if he ever applied for benefits? If so, they may have records that could help you. Their national toll free number is 1-800-827-1000. You can find VA facilities in Indiana using the map at this web page: http://www1.va.gov/directory/guide/home.asp?isFlash=1http://www1.va.gov/directory/guide/home.asp?isFlash=1