Looks like an all plastic pivot shoe

Hello,

This is an old version of our 15-192 pivot shoe. You'll notice that the center cam is quite different but since the opening in ours is larger, your pivot bars should still work with the 15-192. If not, you may need to reuse your original nylon center cams. Take a look and see if you could adapt the modern version of your pivot shoe to work for you. Thanks for posting!