Update
Just letting you guys know where I’m up to.
I’ve installed the air vents, USB Ports, the power button, and the speakers.
Not so thrilled with how the air vents have worked out and I’ll probably go back to those to redo them so won’t post pics just yet. 
The USB ports were simple enough, after a lot of whittling into the side of the case anyway!
Whittling a hole for the USB ports
USB Ports
Cables going to the USB ports
Ok, yeah, they look a bit ugly at the moment but I’ll fix that in a bit!
Power button was easy enough. Drilled a hole into the “bezel” of the frame and soldered two wires to the power button on the motherboard. Extended those wire out through the hole and soldered them to another radio button and epoxyed it into the hole. Then covered it with a brass washer.
Soldering wires to the original power button
Drilled hole for the new power button
Installed new power button
New power button with brass washer
Oh, and by the time I installed all the electronics into the case I was beginning to wonder where the hell I was going to stick the speakers!
No room at the inn
At the bottom right you can see the touchscreen controller, next to the motherboard’s cooling fan. Above that are the USB cables and wifi dongle (which is actually giving me some trouble at the moment, but I’m sure I’ll fix it), and above the the serial R232 PCMCIA card that connects the touchscreen controller to the motherboard.