Have just acquired one with two sets of barrels, seems a reasonable piece of work but know next to nothing about the maker. Appears he was mentored by JMB and had a "factory" next to FN. Any information would be helpful and welcomed. (will try to post photos if desired).
I’ve never heard that he had his own factory. How about some pictures? https://en.wikipedia.org/wiki/Dieudonné_Saive
Interesting, looks like a Benelli. I’d like to see pictures of the proof marks and other stampings on the barrels and receiver.
As to "factory" it may be closer to call it an "assembely" (not sure if that is a word but a place to assemble parts).
I was about to post 1947 from the cursive z date code, but you beat me to it. It’s certainly Belgian but it doesn’t look like a Superposed to me. Here’s the Wikipedia article about John Browning’s protege: https://en.wikipedia.org/wiki/Dieudonné_Saive
Yes, without doubt Liege but as you say Merkel inspired including cheek piece and more. Threw it out here because of the JMB link and the absence of info elsewhere. Que sera. Did figure out one set of barrels is 1947 proofed and the other is 1949. Weirdly enough a neighbour has a set proofed 1948. Small world etc.
With all it's little quirks had I known would I've brought it? Dunno but given I've shot 40 out of 45 single barrel, will I send it back? Ahh...prob not, could be a keeper.