It doesn't look perfect but it doesn't look too bad either, especially considering how it was likely done.
I don't understand why people are failing to comprehend the point of doing this; it makes a lot of sense. I can imagine being able to grip the frame with the additional help of your middle finger would stabilize your shots a whole lot more, as opposed to just sort-of having that finger float above a double trigger. Since these markers run on ramping anyway, it makes perfect sense to me...
The Cooper Union
Mechanical Engineering 2012