Thanks for posting. The part you show with the 'prongs'; do you know what function it served? Is this the top attachment that you're uncertain about? Do you have an undamaged version you could show us? Otherwise your balance resembles our Series 775 Tilt Channel Balance; these however simply screw into the window at the top. Let us know about the extra part you show, and we'll see if we can work something out.
Yes, the third picture with the prongs are the part that attach to the top of the channel and hold the balance in place.
I have added additional photos to show a complete undamaged balance. On the top of the balance is a latch that hooks into a slot inside the top of the channel. They are not terribly easy to get out or in. I have attached pictures of the balance to include what appears to be a model number. Thank you for the help.
Thanks for getting back to us. I believe that our S775-34 can replace this, but we haven't been able to find that clip on top. I don't think they make that piece anymore. You will need to find a way to either screw our balance to the jamb, or perhaps reattach the original clip. Would that work for you?