No.1 MKIII Safety Lever.

[Peter Laidler]

Time Bandid. All you need to know is that whoever made it, invented it, added it or did whatever else to it wasn't an Armourer in any literal meaning of the word, but a bodger with no comprehension of the inner workings of the craft - if you'll excuse the phrase! Even if the shank/shaft had the half moon rotating locking segment at the inner end............ I won't go on. Just replace it and be done with it. Just my Sunday morning grumpy 2c's worth