Window pivot shoe replacement
Thanks for posting! The Simonton shoe you have pictured here is no longer made but the good news is we do have a suitable alternative that should work well as a replacement. Take a look at the 15-259. Carefully compare the dimensions to your existing shoe to determine if it would be a fit.
This shoe is compatible with the Series 159 Coil Balance. To determine the right spring strength to support your sash weight, you'll need to review the existing springs for any stamps/markings. Although, since this is a new balance assembly, it may be a good idea to obtain the exact weight of the sash, down to the ounce, and divide that number by the number of coils in the window.
If your balance assemblies require only one coil balance, you'll need the 15-255 Coil Single Support but if it uses two, you'll need the 15-256 Coil Double Support.
Your existing pivot bar isn't likely to be compatible with the 15-259, so you'll need to replace it with the 26-083 2-1/2" Pivot Bar.