That’s quite a find—congrats. True **6 bore doubles** are definitely on the scarce side, especially compared to the more commonly encountered 8s and 10s. Most were built for very specialized use, so survival rates in *shootable, unaltered condition* are fairly low. Even without a maker’s name, the Liège marks suggest quality continental production. If the bores and wall thickness check out, you’ve got something both collectible and impressive. Not something you run across every day.