Hello,
Thanks for reaching out to us! Your coil balance appears to be the Series 150 Coil Balance which is used a long with our 15-140 Coil Balance Shoe. Unfortunately, your exact shoe is no longer made but this should work well to replace it. Take a look over the dimensions and compare them to your shoe to confirm that this will fit in your window track.
To determine the exact coil springs needed for your assembly, you'll need to remove the coils and look for any stamps/markings that may be present. If there aren't any stamps, you'll need to obtain the exact weight of your sash and divide it by 2. This should give your the spring strength you need.
The other compatible pieces of hardware are the 15-143 Coil Bushing, the 15-144 Coil Bushing Cap, and the 15-145 Coil Support Barrel. If you need to replace the pivot bar, I'll need to see a photo of it removed from the bottom of the sash.