It definitely is an ammo box. No telling what happened 80 years ago. Anyway the box is all Olive now. ThanksThe blue stripe is usually the spare parts chest for the gun. That type should open from the side instead of the top. It is the same size as the ammo box and had the stripe to set it apart at a glance. Early Colt Vickers and Maxim guns also had the striped boxes and the water chest for the Maxim was striped also to set it apart.