Now its time to get that mother board tray mounted and sort out my fan mounting. I threw caution to the wind here, and just started eyeballing things and making cuts. On the fly planning for the win.
Here's a shot of the tools for the job. That belt sander is a new toy, and boy, whether its assisting me in giving a brushed effect to a surface or helping with finish shaping of the aluminum, its turning out to be a real gem:

A few swipes of the file, and a little buzz with the belt sander followed by some light hand sanding with 80 grit emery cloth, and tada:

Whenever possible while making multiple identical pieces, I clamped them together for shaping so they would be the same. This is actually 4 separate pieces halfway through the file and belt-sand treatment (I need to flip them over and sand the bottom in that shot):

Remember the tray? I put it on a little diet:

Here's the frame again, with a few more modifications to accept mounting the tray:

Some details:
(I've since redone these brackets, but the basic design is still the same)


And here it is with the tray installed:



The tray comes in and out easily, and is held in by six 6/32 screws. I used thumbscrews for those pictures, but I'll probably change out the hardware before this is said and done.
Next up, I need to sort the fan mounting and a little wire management prep.