Thank you for your patience in this matter. Unfortunately, we do not have a replacement for this hardware. That shoe has been discontinued for many years and there is no existing replacement. You mentioned you only need the spring, though. While the spring cannot be replaced by itself, we could potentially replace the metal channel balance itself. You would just need to attach the shoe yourself.
If you are interested, please let me know the length, width, and height of the metal channel, as well as the stamp printed on it. I would also like a clearer picture of the top of the balance where it attaches to the window frame.
Thanks for your reply. I am out of town for a week or so. I will send you send you the info when I get home.
Thanks again for your help