Gents, this is why it is a mystery. The note, I believe is innacurate and says thus: Ludenhousen (misspelled)=Exporter
Made for Western Field
1935-1945
Germany
R. Barrel

Do not fire! (Im having the gun properly inspected before firing)

1999

Again, doesnt make any sense to me but it is what is written.

The rib inscription reads precisely: Ant. Bensmann Ludinghaussen I. Westf

Why it says that is anyones guess. Maybe a front for Pire to export to the colony. Who knows. But pretty clearly at least made for Pire in Liege,
likely finished in Antwerp. It remains a mystery. When I have said mystery gun in hand next week, I will post more pics, especially of the rib inscription. Cheers!