Can you post a pic of the uniform? That would help. His collar insignia and wings would be useful because they would narrow down the search a bit. The collar insignia can indicate regular army, reserve, signal corp, etc. They were also made in France, England, and many jewelers in the U.S. The wings also varied greatly, so that would help. It's not Rickenbacker because he was awarded four palms on his Croix de Guerre and his Victory Medal had about six battle clasps on it. Try the guys on theaerodrome.com as well. They're very knowledgeable.