Bi-fold Bottom Guide Bracket, Roberts

Hi, I'm looking for hardware for aluminum bifold doors in a mid century house. The fixed side has a 1/4 inch pin top and bottom, and the moving side has a 3/8 inch bushing(?) that rides in a u channel top and bottom. They mount on the back of the door. The original manufacturer is Har-vey. ... (cont.)

I need four of them!

The photo on top is track on top of closets and other is bottom track.

We have several 1950's 8' bi-fold steel doors and one of them is missing a pivot in the bottom track. Attaching an example of one that has the pivot and other one is missing the pivot. What is name of the missing part?

Looking to update the hardware for my old metal closet door. I have tried to use WD 40 and other lubricants to try to get the door sliding more cleanly, but I ultimately think all of the hardware could use replacing. I cannot seem to find hardware like this anywhere I look though. Help identifying i ... (cont.)