I put the FOB theme back on this Drupal 6 installation. It turns out that it is now straightforward to make it a Chameleon subtheme, so there's no more copy-and-hack; should make Drupal 7 a lot easier.
In the retheming process, with the aid of Firebug and some good Drupal info from the interwebs, I improved some things that had been bugging me.
Let me know what you think. (B)