This is not only interesting but worth more than most would think. This board is bulging, at it's seams, with experience and knowledge. As a student, I am thrilled to speculate on this gun.
None has commented on my questioning the thought that this is not a torched action. It seems righteous to me.
No one has picked up on the odd appearing junction of the barrels and the breech face.
I do not think that the gun was built/finished in Belgium. It may be that the date stamp has nothing to do with the building of the whole gun.
We all know that the German gun industry was 99.9% exclusively military during this time. This leads me to think that the gun was put together, with available parts, by someone in the dark of night.
Either that or it was put together,under florescent light, here. Some ninety years later.
Best,
John