What separates a low grade English trade gun from a high end English fowling piece?
Low grade trade guns typically have sheet metal hardware bent to shape instead of cast hardware, a fixed breech with pins holding the barrel rather than a tip-out standing breech with keys, simpler locks without bridles on the frizzen or tumbler, and less refined engraving and carving. High end guns have a larger breech, cast or chiseled hardware, standing breech designs that let the barrel tip out for cleaning, bridled locks, and more elaborate engraving and carving.