Identifier on channel - 3375 KB. Channel is 34" long. Attached pics of parts at both ends and pull mechanism for 19" spring. Brown end cap as shown.
1/2" square channel window balance




I think we can help with this balance, but the model you're showing me is too damaged to identify. Would it be possible to see an undamaged version? I specifically want to see the bottom fitting and how it connects to the metal channel. Can you also tell me how many you needed?
I think I have a general idea of what you have, but if I'm right then it means this has to be custom made. Since custom balances are non-refundable I want to be 100% sure that we get you the right part. It's best not to guess in these instances.
As for the top sash guide, my first recommendation would be the 18-174. As in the case of the balance, however, I would need an undamaged version to be confident about that.