Aligned hinge on aluminum ruler drill guide, drilled #40 holes. Up drilled, deburred, countersunk hinge and com mount. Riveted hinge to mount with 4-3 soft Al rivets.
Installed radio RS-232 cable and inspected fit. Found com bundle wires would rest heavily against the edge of the bend stiffening the SP-12 mount. Rubbing of wires in com bundle can be addressed by sticking a plastic tie anchor to the aft most bottom of the iBox and pulling the bundle rearward.