Identifying old window balance.

Thanks for posting. Sorry to hear that the S140-11 did not work for you. See our Return Policy here. It looks like you have the 15-180 Pivot Shoe. This shoe works with Series 190 Coil balance springs, sold separately. Based on the weight of the original system, you'd need the S190-540 5 pound spring and S190-640 6 pound spring. This would equal 11 pounds of support. You can reuse your old support clip, see the 15-181 Detent Clip and 15-182 Drum. Let us know if you have further questions.