A quick learner from Traverse City, Michigan says:
June 20, 2019
no markings on any of the three pieces. The third piece is the one glued in the back of the cupboard that supports the stationery slide. These pieces do not attach to the wall. There is a space between the slide and the wall
Bob from SWISCO responded:
June 24, 2019
Thanks for writing in. See our 32-061 or 32-062 Slide Pairs. See if one of these might work for you. You can replace your slide sockets with our 32-018. Keep in mind that these need to be mounted to the back of the cabinet with screws. Let us know if you need anything else.