Pivot shoe

Your pivot shoe reminds me of the 15-177 Col Balance Shoe. It is compatible with the Series 152 Coil Balance, which is secured to the shoe using the 33-072 screw. 

You'll need to remove the assembly to check for any stamps/markings on the coils to determine the correct replacements. There is a video tutorial below with a detailed explanation on selecting the coil balances needed.

The cover/support can be replaced using the 15-143 Coil Bushing, 15-144 Coil Bushing Cap, and 15-143 Coil Support Barrel.

Alternate image for 15-177