Well that was interesting. I blame Synaptic!! When I looked at the residual configurations I was looking for checked objects, like you would if you looked at Installed or Not installed, or All. However, I checked all and removed - saved about 8mb.
The obvious question here is - where did all this crud come from? I'm pretty sure I haven't installed imagemagick or fbpanel ar any time, but little bits were there, not to mention all sorts of other stuff. All a bit mysterious.
EDIT - in terminal the command line way to achieve what Synaptic did is -
apt-get autoremove --purge -y $(dpkg -l | grep '^rc' | awk '{print $2}')
Not so nice to type!!