Simonton window 6100 double hung window coil balance

We should have the hardware you need to repair this window, but I'm afraid I cannot make a recommendation without seeing the pivot shoe itself, which is currently too obscured to ID. Would it be possible to see a clear and unobstructed view of the pivot shoe?

Thank you. It's a little hard to make out in the frame but the design strongly reminds me of our 15-228. This is designed to be compatible with either our 3/8" Series 165 or 1/2" Series 160. You will need to measure your old spring to confirm the best match.