A fine 17th Century English plug bayonet

A fine 17th Century English plug bayonet, hollow triangular-section blade 15.5 in. with inlaid brass decoration; brass mounted hilt with quillons modelled as winged humanoid figures, collar with incised decoration and scalloped edge, wooden grip marked '12', brass pommel with steel terminal; leather scabbard with brass chape, possibly a product of Shotley Bridge.