Progress

Now the left under-desk thing is done too:

Here it is with the top on. The top is made from two pieces of MDF, so that there'd be a hole for the film to hang through in the drying cabinet.

Designing the drying cabinet (and making sure it fit) was one of the more difficult things about this build, and would have almost been impossible without being able to design it with a computer.
The black rectangle down the bottom is where holes and a HEPA air filter are going, so filtered dust-free airflow can travel up the cabinet to dry the films faster. Conveniently, this is also works as an air-circulation thing for the darkroom in general; with another HEPA filter over a fan for air intake in the top right corner of the shell, and this as the air outlet, which is then sucked out by another fan at the top of the cabinet.

Here I'm working out the ideal shelf heights. I'm planning to store chemicals in used wine bottles such as this, and since the height of the shelves is not critical in regards to the computer design and MDF boards, I'm adjusting it for this.

The set up as it currently stands