@Cheese What are the holes for? Especially the larger ones near the edge?
@Michael Kellough The small hole over the rectangular cutout is for a small protrusion on the Blum slides. The underside of the boxes are also drilled at the correct 75° angle for the Blum slide release mechanism.

The large counterbore was intended to hold magnets that were used for actuating a reed switch that then actuated LED's when you opened & closed the drawers. I know you've been here Michael...
![Smile [smile]](https://www.festoolownersgroup.com/Smileys/default/smile.gif)
...the original prototype worked well but when I expanded the scale to 5 drawers the operation was sporadic, sometimes they worked and sometimes they didn't.
That old sample/prototype of 1 issue.
![Smile [smile]](https://www.festoolownersgroup.com/Smileys/default/smile.gif)
I chased it down to the in-rush current was momentarily welding the reeds in the switch together. Not being an EE, I abandoned the reed switches and installed microswitches instead.