"acier comprime" is fluid compressed steel. I have a Bury gun that may fit into this mix somewhere. As I recall, Bury bought Britte and focused them on parts. Like the Brit trade relationship to Birmingham, Liege part can easily show up anywhere in Europe. Gunmkers bought in parts when it was quicker and/or cheaper. And, it was their business to know who made parts and what the various grades of quality cost; part of the education of a master.