Thanks for posting, John! Looking at your pictures, do you see the square-ish nylon piece in the track? Can you please remove that and submit a picture of it separately? It is important to how the entire unit works.
Thank you for your patience in this matter. We have located a possible replacement part for the nylon guide. However, it is not currently online. We will post an update in this thread as soon as we have more information available.
As for the first picture, the metal guide, we have been unable to find a suitable replacement. I apologize for the inconvenience.