In the UK many double guns were made by the likes of Webley and other makers and then sold either in the white or completely finished to other regional gunsmiths. You do see a number that are un named. I have two little 410 single barrel shot guns - one with no name on it, the other with j Hooton, Liverpool and i learnt to shoot with another almost identical gun marked Army and Navy. I have a combination gun marked Heinrich Munch, Aachen, but from serial number and proof marks I identified it as built by Hambrusch in Ferlach and they confirmed this.

From the pictures of the 8x57 look for details on the Belgian proof marks, and that will give more detail. There were are guilds of gunmakers In Birmingham, London, Ferlach, Liege, the Basque Country, Suhl etc and now in Italy - all of whome were and building and making guns for the trade. Many British brands now have their guns made in Italy, but marked with British names.