If that is a sprung rib repair it must be a screw that threads into the bottom rib. But then, how did he thread the hole in the bottom rib to receive it? It appears to be off center, which reeks of more shade tree. I can't see how a pin, pressed in, would hold a loose rib, either. Another observation, if it is a screw that has been dressed down, he did an amazing job of dressing off the top, without any damage at all to the surrounding rib. Could you see where the solder joints on the sides had been broken?
Indeed puzzling, and I would have returned it, too.
SRH
