Okay, I'm pretty happy with this. I'll post the whole file now and work on splitting it. Here are some details.
This is the 'aero' around the fan grille. Hopefully this helps improve airflow.
This shows the 'aero' on the backside of the grille and the PCI bracket retention (bottom part).
Here's my final solution for the PCI top-side retention. Instead of a screw and PEM (which is asking a bit much from DIYers), I have a nut-slot. You slide the nut into the spot then thread a #6-32 screw or bolt in to hold the PCI card in place. I strongly suggest printing this with 100% fill.
Here are the interior sides of the extra ports; HDMI, VGA, dual USB and Ethernet from left-to-right. All these panel mount extensions are available from Adafruit and Digi-Key. The guides are to make assembly easier and give the back panel a little more rigidity since we're cutting a lot of holes into it.
And finally the money shot.
Here's the STL file (fixed, Rhino3D kept resetting the font to Arial ... grr):
https://drive.google.com/file/d/1wjqKt0 ... sp=sharing
You'll want to print it face-down; all the lettering is indented and shouldn't pose a problem (the original 1000 was embossed which would have). Feedback welcome.