I don't care if mine are on the approved list. They are toys. And the price was so right. I can play with 2 for the price of one.
As to the machining. It may be quality control. That they didn't check the tolerances or something. Or the parts went out without a machining step being done.
Or, like said above, they are not meant as real safety notches, just fake look alike notches.
I still haven't found out what the defect is. Why it doesn't fit. Hammer machining or cylinder? Or adjustment, or what.
It really isn't a big issue with me as I don't intend to carry the gun. Just load and shoot at a range, or someones yard.
But, someday, I will answer my questions.