I just installed one of these in my rifle and noticed that the "upgrade " was identical except for the triangular shaped opening.
It had been "rounded out", so that the little ears were smoothed off where they would hang on the pin.
Seems that it would be an easy job to do with a moto tool, saving a few bucks.
I've made several of these and yes, it's fairly easy. I use a dremel
There is one other way to do this but this way works well.
Let me know if I can help!