The shoe

Looks like you need a new top sash guide. We sell a ton of these, but it's unfortunately not possible to ID what you have from this photo. We need to see it fully removed, shown without obstruction, and in undamaged condition.

Once we have that, I can check our inventory for a match. In the meantime, you may find the video below to be helpful.

This top sash guide appears to be a match for our 18-069. Make sure to review all dimensions before placing an order just to be safe.

Alternate image for 18-069

Alternate view of 18-069