See Message #4036. An educated guess is he served with 6th Marines, 2d Marine Division and 3d & 21st Marines, 3d Marine Division. All tactical units were elements of Fleet Marine Force (FMF). The DD Form 214 wasn't adopted until well after the war. The correct form number will be in the extreme upper or lower left corner of the form. It's very important to BE accurate if you WANT accuracy.