This door is a Oldie. Made by Marshall Aluminum Products Co. Irvine CA. They are still in business but do not make mirrored doors any more and have no Old parts.
This roller assemble has a pressed on bearing that the plastic wheel was attached to. So I can't just replace the wheel. The three holes in the guide at the end, is where the two little screws hold the guide in place inside the door. The end with the screw head showing is 9/16 wide and1 1/4 tall. The broken plastic wheel was 1 1/2" OD. Where you see the pressed on bearing, that part pivots back and forth and the set screw in the end locks the wheel in place. I guess?
Do you have something that will work for me. I'm fixing the door for a neighbor. She's 70 something.
Thank You,
Charlie