Thanks for posting! Your coil shoe can be replaced with our 15-180 Coil Balance Shoe. It is not an exact replacement match but we have recommended this as a replacement for quite a few customers. Just be sure to review and compare the dimensions below to confirm that it will be a fit.
This shoe is compatible with the Series 190 Coil Balance Spring, secured to the shoe using the 33-073 screw. To determine the spring needed for your assembly, you'll need to look for any stamps/markings that will indicate the strength of the spring. If there are none, you'll need to obtain the exact weight of the sash and divide that by the total number of coils in the window.
Since your assembly only appears to use a single coil you may also need the 15-186 Coil Balance Clip as well as the 15-182 Balance Bushing.