Now that I've decided which parts will be on the shelf I finished installing the nut plates. I also final fitted the hinges and drilled the holes for forward hinge and riveted it to the sub-panel. Then I attached the shelf to the installed hinge with the hinge wire. Marked and drilled the shelf and hinge for riveting. With it now clecoed in place I swung the shelf under the instrument panel frame, drilled thru the frame and shelf and installed nut plates on the frame and inserted a couple of screws to hold the shelf up. Then I riveted the shelf to the hinge and just like that, it's done. Lastly, I drilled and then bolted the transponder holder to sub-panel and installed the transponder.