Side drawer guides used on 1980 Childcraft baby furniture

The dresser drawers have wooden center mount slides. I can find the glides for the center mount, but I have been unable to even describe or find the side guides. These guides are attached to the outside corners of the drawer frame. They keep the drawer inline and keep it from falling forward. Note that the bottom of the glide fits into a hole. The first photo is upside down. The second shows one that is still working. Please tell me what this piece is called and if you have it or can tell me where I might find it.