The bracket broke on another drawer. Slips into an "L" shaped opening on the side rail. Hardware from 2001.
Bob from SWISCO responded:
May 10, 2021
I am afraid we don't sell a bracket like this. I can't be certain, but see our 32-018 Drawer Socket and the 32-056 Tracks, or the other sized tracks I've listed on this page. Look at these parts over and see if you think these could work for you.