Broken Hawken rear sight

[dsotm]

Anyone know if this can be put back together or do I just need to get a new set of sights? Not sure what happened but it just pops apart with minimal pressure now.

 

[Squeeze]

Im not familiar with that particular sight, but it looks like a roll pin has broken. (by the unfinished silver spot on the right side of the horizontal screw) Can you tap out what remains, and possible replace a roll pin? If not, try Numrich for a replacement