I remember the Laurona double barrels from back in the 1980's when I first saw them at the gun stores. They were a lower price shotgun. Some really had nice wood stocks and finishes, etched engraved receivers with coin finishes, and (if I remember correctly) they had a 12ga double model which also came with a set of 20ga barrels.
If yours has some pitting and a mark on the barrel (not really sure what you mean by a mark?), and it's probably a single trigger with manual ejectors? Choke full and mod? A 2 3/4" chamber. It's worth around $250.
Price will be lower if that mark on the barrel is a dent. Also, if the butt stock was cut short.
Price will be higher if it's auto ejectors, and screw-in chokes. That should bring it up to about $450
