The corners broke off?
Cheap fast and simple cure, get four barrel washers (large washer with small hole) or cut four triangles out of black/white plexi to use as washers, and just put them on top of the pieces, screw/bolt it back in.
Oh, that's clever. Yes, that'll do the trick nicely until I have more time to get around to doing it properly. Yesyes. Thanks for that tip.