Window balance track replacement / fix

I think we can supply this balance for you, but I'm afraid too many important details are obscured so long as it's installed. In order to proceed, I will need to see your balance removed from the window and shown without obstruction.

I'm chiefly interested in the knife lock shoe at this stage. I have a good idea what the base channel configuration is, but there are a ton of variations of that shoe and the only way to narrow it down is to see it removed. 

I'd also like you to confirm that the metal channel is 25" long (it should be), and the exact weight of the sash, down to the ounce. Finally, how many did you need altogether?

Sure thing, we'll be here to help whenever you can get this info to us.