The more I am thinking about it, the more I believe that our enclosure should be made of an extruded aluminum profile for the bottom and side sections. Something like this one from a Chinese OEM manufacturer for example. The side panels would be flat, but the bottom panel would have the same fins as the one shown on the picture, in order to facilitate heat dissipation.
For the front, top, and back panels, we could go either with aluminum or steel. Aluminum would have the benefit of being lighter, easier to machine, and easier to etch with laser, thereby removing the need for silk screen printing. And if we were to use aluminum, we could use a continuous hinge that would connect the top and front panel to the bottom panel for easy access to the internals of the machine. I used this type of hinge when I built the over-the-top Monolab Trunk, and I loved them.
With such a design, all we would have to add would be foldable feet that would allow the device to be raised by 10, 30 or 45 degrees, thereby improving heat dissipation through convection.