Need this part....

Thanks for reaching out to us, Eric. Based on your photos, I recommend either our Series 380 or Series 385 channel balance. The best replacement option depends on the depth of the bottom shoe so you'll need to measure as shown in the image below. There should also be a stamp on the balance's metal channel that will indicate what strength option you'll need to select. If there isn't a stamp, you would need to weigh your sash and refer to the chart under the product description on the S380 and S385 store pages to determine the appropriate spring strength option for your balances.

Comparison of the S378, S380 and S385 balance shoes.

For the 16" balances, you'd want the 1520 strength option and the 2120 strength option for the 22" balances. Your top fitting does look different from ours but we believe that our balances will work perfectly fine.