German Artillery Shell ammo box??? Please help.

[excalibr]

I've had this box for a while, and never knew exactly what it was! The 'story' was that a guy bought a US Army Jeep and this box was in the back. The jeep was in Germany or somewhere in Europe. I'm not familiar with the markings on the front of the box. It is a VERY well made box with dovetails and nice latches. It looks like it held one large shell, and the wooden slats on the top/bottom are staggered so that cases could be stacked easily (I'm assuming that's why). The box measures approx. 29" wide, 6 1/2" tall, and 6 1/2" deep---those are inside dimensions. ANY info would be great! Thanks!