This is the classic United States Navy standard divers knife, aka Mark V knife. This knife is in like new condition fully polished condition. This knife was made by DESCO (Diving Equipment & Supply Company). The brass scabbard is stamped DESCO. 

The wood handle, stainless steel blade, leather strap, etc, are in wonderful like new condition. The brass scabbard has been professionally polished to a brilliant shine. This shine can easily be maintained with occasional hand polishing, or a consistent patina can be allowed to form. The brass is free of any dents. There are a few tiny imperfections in the brass, but essentially it looks like day 1. 

A knife like this looks incredible by itself or displayed next to a helmet!