Window coil balance shoe
Thanks for posting! You can use the 15-180 Coil Balance Shoe to replace your existing shoe. This shoe is compatible with the Series 190 Coil Balance Spring secured to the shoe using the 33-073 screw. Your coil appears to be stamped with either a 6 or a 9, so you'll need either the S190-640 or the S190-940 to replace it.
If you are unsure of stamp, you'll need to weigh your sash. You'll need the 6lb coil if the weight is closer to 12lbs and you'll need the 9lb coil if the weight is closer to 18lbs.
The compatible clip is the 15-186 Coil Balance Clip used along with the 15-182 Balance Bushing.
The coils will be way too strong for the window. Best-case scenario is that the window just won't close; worst-case is that the sash shoots up and the framing and/or the glass becomes damaged.
The difference is between whether the window weighs 12lbs or 18lbs. That is far to wide of a range for the coils to be interchangeable.
I hope this helps!
