Company E, 324th Infantry
It is now legal to purchase all regulation-size U. S. decorations and medals - except the Medal of Honor. If you'd like to avoid the wait, I can arrange a complete set of decorations, medals and badges - everthing your Dad was authorized - very reasonably. E-mail me direct.
By the way, your Dad must have been somewhat of a "hard-charger". It's very unusual that a motor vehicle mechanic would have been authorized the Combat Infantryman Badge (CIB). The CIB was created during WWII and was awarded almost exclusively to men with infantry occupational specialties (MOS).