About this 3D model

In the post mortem of my wife's PolyBot assembly, one of the things she wanted was a hole to put a screw through the servo mount to hold it to the platform.This thing is the exact same as the previous version, with the addition of an M3 sized mounting hole, and an indent for the matchich hex nut on the 'bottom' side of it.I considered having more holes for more holding goodness, but I'm still sticking with the minimal fasteners design principle.