Socket bayonet, unknown

Bayonet collectors love a challenge but the plain simple truth is that not every bayonet can be positively identified. This lovely socket bayonet is one of those challenges, priced accordingly. Blade length 17 3/4 inches (450mm), Overall 22 5/8 inches (568mm), Socket length 4 1/8 inches (104mm), socket diameter 20 - 21mm, blade width at socket (widest part) 23mm. Good luck.