Ernie,
It sounds like a neat old Browning Auto-5. It was made by Fabrique Nationale Armes de Guerre in Liege Belgium. It was made under the Browning patent and should be marked Browning's Patent Depose.
The choke is marked (cylinder) and the reference to Special Steel indicates that it was made for export to the US. Guns destined for Europe would have been marked Acier Special (Special Steel in French) It should also have the Browning Arms name on the barrel.
The reference to Krupp confuses me, normally that would refer to a type of steel but that was marked in English so I can't explain it.
The difference in color of the wood is likely to be caused by oil soaking into the head of the stock. As these were mechanical contraptions many owners oiled the heck out of them and the oil drains into the end of the reciever while the gun is stored muzzle up. As oil will soften the wood and make it punky it can be a real problem.
Is the writing/engraving you refer to the words we already covered or are there decorative designs marked on it? The more common designs are vine and leaf type engravings.
Your gun will have short (65 mm) chamber so dont try to shoot standard 2 3/4" 16 ga shells out of it.
This is the kind of gun I am most interested in and hope that I may be able to learn more about it. Thanks for sharing it with us,
Jeff
