Damaged channels
Thanks for reaching out to us! The channel balance you have here appears to be the S751-25 Channel Balance with a 15-014 Knife Lock Shoe. The stamp would remain the same.
They are likely attached at the top of the channel using either the 19-029 (short) or 19-030 (long) S-Clips but you'll need to double check.
To confirm that this is the correct replacement, be sure to double check the length of the channel. These balances come fully assembled.
The part these balances are installed in is called the jamb liner. If that needs replacing, you'll need to reach out to your local millwork to inquire about what you replacement options might be. Apologies that we cannot be of help with this part of the repair!