Kitchen drawer rear center track holder
Thanks for posting. We carry a number of center drawer sockets, as you can see here, and it's tough to tell if any match this incomplete fragment without knowing the dimensions. Take a look at our selection and see if you think any might work as a substitute. Also take a look at the total track replacement kit, the 32-053.
I understand that you only wanted to buy the back bracket. I only mentioned the full track kit as one potential alternative, if all else fails.
To be honest, that may be our best option regardless. I have been unable to find any socket with an internal measurement of 1-1/2" x 5/8". The closest we have to that is our 32-009; this has an uneven opening, though, measuring 1-1/2" wide at its widest and 1-1/4" at its narrowest. The height of the opening is also 15/32", which is much smaller than yours.
All the same, it appears to be our best option. Look it over and double check your measurements to see how they compare. If all else fails, the 32-053 track is always an option.