After the successful fitment test of Revision A, it's time to get down to business actually building an usable enclosure. For one thing, it actually needs a handle to be luggable and provide some sort of protection for the components instead of leaving them completely exposed to the world.
A rectangular frame built of aluminum extrusion bars will help address both requirements. The top bar will host the carrying handle, and the frame will provide some protection against impact from the top, bottom, and sides. Assembling the frame was occasionally frustrating because M3 nuts easily slid out of their designated position on the aluminum extrusion. I printed some inserts to keep critical individual nuts in place and also printed a strip to keep a set of nuts in formation relative to each other.
Revision A had feet towards the middle and it didn't provide enough left-right stability. Revision B moved the feet out to the bottom left and right corners.
The rear of the enclosure is made of laser-cut acrylic because it was the fastest way to get some coverage for a large plane. (It took a fraction of the time it would take to 3D print an equivalent.) Since acrylic is brittle, this is not a long-term solution but it is good enough for basic protection separating errant fingers and wires from the spinning fan blades.
After everything was assembled and stood upright, things started flexing in response to real-world factors like gravity which were absent from a CAD drawing. I credit the root cause to bad design on my part. In the meantime, in order to salvage rev B I hacked up a fix by printing some flexible brackets using vase mode to keep things in place.
Revision B also taught me the PCI Express extension cable is not designed to be bent around so much. After being bent in many different ways to explore different component layout ideas, it started causing system instability and needed to be replaced.
I have a usable luggable PC now but there are still important goals to work towards for future iterations yet to come. As usual, the links above plus more details (some important, some trivial) are available on the full build blog.