I planed some more cherry down to about 3/8" to make five dividers for the cubbyholes. Not wanting to make any particular part of this cabinet tool specific, I sized the cubbyholes rather large - large enough to house the widest of my smaller planes. The cubbyholes are wide enough to hold more than one plane if needed.
The thinness of the dividers made clamping with regular clamps a bit difficult. I decided to apply pressure with a couple pieces of wood clamped across my bench . As you can see from the glue squeeze-out, it worked rather well.