Seems to be working for me in iOS 8
that tiny screw is a M1.6 screw and a 8-32 x 5/16" set screw in the back of tha trigger frame is used to restrict over travel of the sear extender.
I need valves for 2 rental mags, so their cosmetic condition isn't a concern. Should be complete, but I don't care if they need rebuilt. Looking to