The Commodore VIC 20 has a plastic outer case that splits into a top and bottom half. The rear of the top half has tiny fragile pins that slot into to lower half to hinge the case together. I'm told many of the Commodore 64 cases are the same.

These pins break really easily. I created this part to replace them when they do. Just slot this over the remaining rib after a pin break. It holds pretty well with friction, but a bit of glue with a long work time will hold them permanently (I used Goop).