White plastic stopper

Hi, Jay.

Thanks for reaching out to us. It sounds like you need new top sash guides. Can you remove one in undamaged condition and show us photos of the front and sides? Written-out dimensions would also be a huge help. Those details will help us narrow down some options. 

Thanks for the photos! Your top sash guide appears to be an older version of our 18-066. This is what we typically recommend as a replacement for your type of top sash guide. Although, I am not confident that this will work as because of the rail built into the sash. Take a look over the design and dimensions below and see what you think.

Front view of 18-066

Side view of 18-066