Replacement Channel Valance and cover
Hello,
It looks like you sent our part experts a request for similar balances back in 2019, which you can view here. We just sent over an order link and price quote to have a rivet attached to the top of our S770-22 (22F) balance to accommodate an s-clip like our 19-029 or 19-030. With that being said, you'll need to make sure that the balances in this window use the same terminal clip at the end of the pulley as shown below.
As for the balance cover, unfortunately, that is not something that we can supply but a local hardware store may carry it. We apologize for the inconvenience but just let us know if you have any other questions. Thank you!
Unfortunately, the minimum order for these custom balances is two. Also, I would not recommend trying to use a stock balance on one side since they are designed to be attached to the top of the window jamb with a screw, while yours uses a rivet and S-clip.