Window piece
Thanks for your post! Your balance shoe looks like it could be replaced with the 15-177 Coil Balance Shoe. I'm fairly confident it should be a match but take a look over the specifications and compare them.
You'll need the 1/2" wide Series 152 Coil Balance to replace the springs; attached to the shoe using the 33-072 screw.
To determine the correct coil weight option, look for a stamp/marking on the existing coil(s). If there are none, please see the tutorial (tagged below) for instructions on selecting the correct coil weight option.
I do not see the existing coil supports (covers) so, I am assume they may be damaged. If so, you'll need the 15-143 Coil Bushing, 15-144 Coil Bushing Cap, and 15-145 Coil Support Barrel. All three are used together to create the support.