Coil and bracket
Thanks for posting! You coil assembly appears to be an older discontinued shoe that is no longer available. The good news is that we do have a replacement we can recommend for you.
Simonton brand coil balance assemblies are being phased out as their pivot shoe is no longer made but we do have a replacement solution that will work for you. Take a look at the 15-259 pivot shoe. Carefully look over the dimensions below and compare them to your existing shoe to determine if these might be a fit. You'll need to use the 15-255 single support to replace your cover.
This shoe should fit well in the track, along with the Series 159 coils springs. To determine the coil springs you'll need to confirm the stamp from the existing springs. If there are no stamps, you'll need to obtain the exact weight of the sash. If you need to use the sash weight to determine the spring strength, you'll need to take the total weight and divide it by the number of coils in the window.
You should also keep in mind that you will likely need to replace the pivot bar. The one compatible with the 15-259 Pivot Shoe would be part 26-083.