There is a lot known about
Pieper and his Bayard trade marked guns. If you can read French, there is an excellent book about
Pieper.
If you take the barrels off, you will find the Belgian proof marks. You can look them up here:
http://damascus-barrels.com/bp.htmlPieper was in business for very long time. His son Nicholas was running the company when they started using the Bayard trademark.
It would help if you could post some pictures of the gun. I have a several
Pieper catalogs and may be able to id the model. I own several
Pieper guns, including a Bayard 28ga.
Pete