Zenith 32/36 NDIX Throttle Body Shaft.  The throttle bodies of the 32/36 are cast and the shaft is Brass.  It is designed so the Brass Shaft wears over time.  Fortunately, the cast throttle body does not.  A complete carb rebuild should include replacement of the throttle shaft.

We also sell this as a KIT with the Screws which is a better option.  

Installation Note:  The shaft does go into the throttle body in a specific direction.  Take note on dis-assembly which end sticks out of the casting further.