If I were you, I would try to find if there are any surviving members of your grandfather's platoon, who would have served right next to him. It would be worth contacting them and trying to get some stories about their particular experience. Perhaps one of them has/had written something - whether it be a journal at the time, or a memoir of some kind afterward. They would almost certainly remember your grandpa.
These platoons often met up for reunions, though most have stopped simply because there aren't many living or able bodied WWII veterans anymore.