I made progress on the credenza I am building for my office. Pictured above is a look at the internal hardware needed to support the push-to-open drawers. The rod between sides is used to synchronize the slides so that a push on one side of the drawer face will trigger the other side as well. The rods are connected to the devices which propel the drawer forward when triggered. They in turn are connected to the actual drawer slides. Having installed this arrangement on something like 120 drawers throughout the house, I have gotten quite proficient at installing them.