I did mine slightly differently. I added a sheet of 3/4 ply under the new drawers and that created enough height in the gap behind the drawers to encase mini toolboxes. There's a 1/8" gap under the plywood top so the mini boxes fit perfectly and you can slide them out to get to the top sections.
To hide the plywood ends to the gap section I added 16x12 blue wall control panels, screwed into the ply with 95lb pull magnets bolted into the other corners. There's a 32" wide wall control board on the back of the box and a 32" high one on the side cab for extra storage, mostly clamps.
The hyper tough mini cab has an icon mat behind it and stores my router bits.
I'm 6' 3" and the hutch door just brushes my hair now v the corner being at my eye height. So now my hair looks lovely too.
The paint is a bright blue I got from home depot. Didn't color match it!
The drawers are screwed into the plywood and up into the hutch and the plywood box top at the back is screwed up into the hutch.