Google the 347th Army Airforce for unit information or a reunion webpage and do a Google Books search too. Someone might have penned a memoir about it.
Have you tried getting his Service Records form the NARA? His might be the 20% that survived the fire of 1973.
I don't see where you say his DD214 doesn't match what he told you. He enlisted in Oct 1940 before Pearl Harbor Attack. The U.S was in the process of beefing up the military presence in Hawaii. Schofield Barracks is a Army Base with an airfield in Hawaii and he very well could have been on a ship heading to Hawaii with others and supplies. If they were at sea on Dec 7th 1941 the ship could have been diverted to keep them safe and supplies out of Japanese hands. He said he was in India and in paperwork it is noted in "Battles and Campains" - "India-Burma" and he was issued a Asiatic-Pacific Service Medal/Citation If he didn't get a purple heart it might be an oversite of the time or it was an engine fire not connected to his military service job or active battle. Read up on criteria for Purple Hearts, it has changed over time. His unit's "home base" could have been Australia and he was sent to India from there and returned there, never being offically transferred.
Also the NARA has other records not online, still in paper form or on microfilm. You will have to go to a NARA library to research them. Some microfilms may be available through a LDS Family History Center. http://www.archives.gov/research/arc/topics/ww2/http://www.archives.gov/research/arc/topics/ww2/