So I really was going to stop mucking around, but storage was getting tight and I saw a good deal on a 3TB drive

I had an idea for that drive cage I yanked out last time: a not-so-hot swap bay in the wasted space of my quintuple 5.25" cage (the big enclosure on top in the OP, completely empty except for a dead optical drive and some cables). So, yesterday I tore down the whole PC, pulling off both side panels and all of the front 5.25" bay covers. I got a ton of dust out of the front panel and around the drive cages. The GPU and RAM came out again so I could yank and wiggle the 500GB HDD out of the floppy/card reader cage I'd jammed it in, and I finally yanked the years-dead optical drive.

I seated the loose drive cage inside the larger enclosure, but no screw holes lined up, so I ended up tying it down with heavy-duty twist-ties and wedging the main trunk line from the PSU into the gap. My drives slid in through the front and I put an 80mm fan w/ blue LEDs in front of them to pull in air (the whole box is 5*C cooler now), put two grill pieces in front of that and replaced all but one of the bay covers. The fan and grills are just kind of jammed in place, not screwed down at all, so I might refine that a bit, but now I have a cooler case, more accessible hard drives, and a light up grill in front. I left the SDD where it was in the original pic, because it looks cool



That's foil jammed on either side of the grill to close the gaps against dust.