Window Balance
Thanks for the additional photos. Your window balance shore appears to be a closer match for the 15-199 Pivot Shoe. To determine the correct replacement, you'll need to carefully review and compare the dimensions.
The compatible pivot bar is the 26-378.
From what I can see, the coil support appears to be similar to the 1/2" Coil Double Support. These use the 1/2" wide Series 160 Coil Balance. To confirm that this is the right series, you'll need to confirm the width of your springs. If it is 3/8", you'll need the Series 165 Coil Balance, used along with the 15-204 Coil Dual Support.
If your balances do not have stamps on them, take a look at the video tutorial below for instructions on selecting the correct coil weight option.