Thanks for the input fellas. It was in a German museum at one time. I looked up that tag for info back when I first handled the gun 3 years ago as the guy who had it swore up and down it was German because of that tag. I say French all the way based on the Darne similarities, but I have found no makers mark of any kind anywhere, and I have had it apart down to the barest of bare pieces. Same serial number everywhere, but no marks of any kind after the number and the proof marks you see. Regardless of anything, a very cool piece in my opinion.
Everything functions well mechanically, I need to replace a few screws and put it back on face, but the design makes that pretty simple and straightforward. The wood needs some serious attention though, not quite sure what I will do about that yet, but I will get it back to a shootable condition. Be sure to keep an eye out at the big SxS shoots in the future, I will use it for a round or 2.