Top Panel Guide, Pella

Hi, I have a Pella sliding glass door with a screen that is missing some sort of top track or guide. The door is old, I beleive around late 80's. I've searched through replacement parts, but can't figure out exactly what is suppose to go up there. There is about 3/8" of space between the top o ... (cont.)

I'm trying to find this part for my patio sliding door. it screws into the top of the door keeping it on the track. about 1" by 1"

This plastic piece, I believe had a felt inset on the glide. I need 9 of them.

One is missing from the top of the sliding door. This is what I think is missing. Door is rubbing and binding a bit.

We have a hotel we supply with their hardware. Their sliding glass doors are very wobbly on the top. What can they use to have them open and close smoothly? This problem also allows a lot of noise to enter the room.