Well, it is a beautiful gun. A 28ga double rifle would give a bore of .55". If it is a DR then it is missing the rear sight. If it is a shotgun, like Geno, the engraving makes no sense to me.
Pictures on the web rarely do a gun justice. I believe that is a higher grade of damascus than it appears. It is etched, which was common for German guns and some high end Belgian guns.
Who would have a 7 pointed crown?
Teschner was succeeded by Collath. Take a look a the Collath double rifle at bottom of this page:
http://www.littlegun.be/arme%20allemande/artisan%20c%20d/a%20collath%20w%20%20gb.htm A similar, but less grade gun.
Pete
