I am looking for the plastic clip as shown in the photos for upper tilt window tube balance. The above plastic connects to a 5/8" tilt tube balance. The bottom of the half of the window tilt tube balance is connected to a clip very similar to your series 600 pivot clip.
Paul from SWISCO responded:
October 26, 2018
Thanks for reaching out to us. Take a look at our 15-015 pivot shoe. Look over the width, height, and thickness of your pivot shoe to see if our replacement would work as an alternative.