English L1A3 bayonet, first model by Enfield, Unusual NATO Stock Number. (ABCN169-1)(K38)(JN63-2)

English SLR. Semi-automatic rifle L1A1 Cal. 7.62 . First model. Excellent parkerized fullered Bowie type blade with a long fuller. Broad arrow /I\ and 58 on the ricasso. The blackened pommel is brazed to the blade tang and is marked:  /|\ Ð. (=Enfield)  T- type mortise slot. L1A1 type "tailored" crossguard with a muzzle ring MRD 14.8. Blackened metal grips are both marked /|\ Ð and are riveted to the tang. Left grip scale is marked with an unusual NATO Stock Number (NSN): L1A3 960-0011 over 0257. 0011 is canceled and replaced by 0257. No serial number to the right grip scale.
Excellent and correct blackened steel no. 5 MK1 scabbard with a round frog stud and a brass throat. No dents to the scabbard.

Very curieus NSN marked SRL bayonet. Never seen this partly cancelled and corrected marking before.