I have a Charles Boswell 12 ga, 2 1/2" chamber, 30" Damascus barrels. I'm trying to decipher the proof marks but that's a new area for me. If i can figure out how to post pics I will. Until then are there any books that explain the markings?

Also, this is there is not an address on the rib like I've seen on other doubles. Is there a way to tell if they are replacements?