Paying $35 for a plastic box really makes me a bit upset. I paid the money and had it shipped from Europe because I thought there was no alternative. But there is -- you can print one. I went to Thingiverse.com and found a project titled, "Advanced Ultimate Box Maker." This was the third iteration of a rather simple parameterized box originally posted on Thingiverse. The author made available his code written in OpenSCAD. This version had a lot of variables for configuring the PCB feet, panel cutouts, fan openings, etc. but it wasn't enough for my purposes. I had to learn enough SCAD to be dangerous, and after a few days of tinkering with it I think it will produce a usable box for this project. I had to add a fan opening in the bottom shell, change the hole sizes for the fan on the back panel to 6mm to accommodate the rubber isolation plugs included with the Noctua fan, and a couple minor things. Most of the box could be generated using the customizer in OpenSCAD.

I decided to use the PCB front panel that Paul had designed because it had all of the lettering and looked pretty professional. The bottom shell, top shell and back panel are available to be printed. Here's a look at the results:

The bottom of the bottom shell, showing the fan opening.

You can download the .stl files from this project and print your own case if you wish. The ripples on the top and bottom shells are due to the z-offset of the nozzle not quite correct over the print bed.