One of the older hard disks has become non-deterministic, but it's non-essential and I've pulled off the stuff that I'd like to keep.
And I am so glad that I spent extra for a removable motherboard tray. This build would have been impossible without one, thanks to a very long graphics card with a PCI-E power connector directly opposite a hard disk power Molex. And as luck would have it, that's the non-deterministic hard disk. That'll be fun to remove.
Lessons for next time:
Check that the driver disk you built a year ago still works. I ended up in the interesting situation of needing drivers from a hard disk to access the drivers on that hard disk. Laptop + Intertubes + USB pen drive to the rescue!
Check what cables come in the motherboard box. Asus were a bit stingy, and only gave me two SATA cables. They also didn't give me a serial port blackplane, even though the motherboard has a header for one. I was rather hoping for one, as my Palm Vx speaks RS-232 rather than USB.