Hard to say without photos.
If a run-of-the-mill damascus shotgun from an obscure maker in fair condition, could be a couple hundred as a wallhanger.
If it has any deluxe features (engraving, fine wood, etc.), it could be more.
If made by a known maker, it could go higher.
If it could be documented to have belonged to a historical figure, it would go up.
If in excellent condition in a case with accessories, it'd go up.
Denis