Vintage is a burden to most shooters/hunters. They prefer easily serviceable shotguns that can be fitted via shims or inexpensive adjustable or bolted stocks, steel proof barrels and screw in chokes. Like a poster said a while ago, a good gun is the one that makes you smile when you pick it up and not cry when you drop it, and that excludes classics and vintage guns.

Add to that laws that mandate FFL (USA) or dealer to dealer licensed shipping (EU) and the downward trend is understandable.