I can now confirm that restoring from Time Machine is stupidly easy.

1) Leopard finishes installing, Mac restarts
2) Migration Assistant starts itself and asks me if I want to restore from another Mac, another volume on my Mac, a Time Machine backup, or not to transfer info at all. I choose a Time Machine backup from the internal 80 GB drive in my G4.
3) Leopard scans my drives, finds "1 Time Machine backup available" from my internal 80 GB drive. It also found my Airport Disk drive and lets me know I can log in to it to look for backups there if I so desire (thanks, but no thanks). I pick the discovered backup from my 80 GB Time Machine drive.
4) A list of stuff shows up: Users, Networking and other settings, Applications folder, Files and Folders from my old OS X installation. It also tells you how big each option is.
5) I open up the Users drop-down and select my account. I deselect the old user account for Postgres back when this box was my dev machine.
6) I click "Transfer".
7) Magic ensues.

Yes, my friends - stupidly, stupidly easy. So much so, in fact, that I am now stupider for having used it.