You have enough to request his records from the National Archives Military Records Center in St. Louis. Use the key word NARA and you will access to their main page. Unfortunately, they had a fire in 1973 and a lot of records from that era were destroyed. The options are to find a discharge paper, DD214 or equivalent. Many veterans had their discharge paper recorded by their county recorder to make certain it was available if they had later claims with the Veteran's Administration. If a veteran had dealings with the VA(health, schooling, real eastate loan) those records may be retrievable too. In each case the veteran would have to document his service and copies of whatever was presented should be in his file. The personell file is the most detailed. If that is not avaialble you can get a less detailed, but still informative, look if you can dig up the other stuff.