I have a side by side 9mm shotgun/22LR with a Belgian proof mark. The gun appears to be well made, has extensive engraving on stock, receiver and trigger guard. It is loaded via a rolling block; it does not have a break action. The barrel selector consists of a small lever on the hammer that pivots a plate into position to strike the appropriate firiing pin. The gun was owned by a now deceased friend so I have no way to trace the history through ownership. I can find no manufacturer information, model numbers or serial numbers. Any ideas about possible ID?