Singer 15-22 1884 fiddle base sewing machine genuine oscillating hook bobbin case Simanco 2074. Lot C

I bought out a company 6 years ago with a hundred boxes of mixed vintage and new sewing parts and this bobbin case and bobbin was among them. It was labeled Singer 15-22, 1884 fiddle base sewing machine genuine oscillating hook bobbin case Simanco 2074. The condition looks pretty good it appears some thread or material got stuck and someone try to loosen the screw and was unsuccessful.