I'm finally typing from a shiny new Flidas install on my Thinkpad T61.
This has been a bit of a comedy of errors, but it seems painfully obvious in
retrospect and so I wanted to share.
Much as I hoped my problem was with unetbootin and/or the disk creator
utility on T7, nothing changed after running another netinstall from another
USB stick created with the dd command. I still saw a black screen with no
command prompt, no cursor, no nothing.
No idea why I closed my laptop, but I did. It went to sleep.
So I opened it back up again and tried Ctrl + Alt + F1 and/or Ctrl + Alt +F7
until I got a command prompt and sudo apt-get installed fluxbox and then
Abrowser.
Everything's fine now.