Channel balances
We are having a difficult time identifying your current balance from the pictures you submitted, would you be able to send us more close up pictures of the top and bottom attachments?
Our 18-171 top sash guide should work as a replacement option for you.
As far as your balances go, it looks like you have either a Series 380 or 385 channel balance.
The difference between the two series lies in the bottom shoe attachment.
The series 385 balance has the 15-004 shoe which is slightly larger from front to back, as illustrated.
Once you measure your shoe as it is pictured here, you should be able to determine which series balance you need.