I would think he would want to do objective research on this, and leaven those facts with input from vets, but that would be the way I would do it if writing a novel set before I was born.
Problems just with what I skimmed there: There was no DOD, no VA, prosthetics were primitive. PFC's were not gunners on bombers, at least they didn't stay that rank long. There is a well documented story of a SSG offering to trade jobs, rank and all, with a corporal infantryman. When the infantryman finds out the SSG is a gunner on a -17, he says "go to hell"