Bi-fold door hardware

Our house was built in 1987. The bi-fold doors have a part that slides in the top track. A couple of these have fallen out and are lost. I can't find anything that looks like a replacement. The photo has 3 views; the part in place with a spring post in it, the part in the track without the door post, and removed laying on a table.

Any suggestions about alternatives?

Looks right to me. Thanks much. I ordered 3.