In case anyone's interested, I've resuscitated the blighter. Reinstalling osso-systemui* brought back the themes and maemo-icons-203 brought back most icons. Then it was just a question of finding which apps had missing their icons missing or were otherwise broken and reinstalling those. Now the only two remaining problems are:

1) I have a mouse cursor on the screen. It follows the stylus which is kinda cool and it does not bother me so I am quite happy to leave it as it is but if someone knows what might have caused it I would be quite interested.

2) The icons for status-area-orientationlock-applet is missing and I cannot reinstall the package. It keeps telling me that it cannot be downloaded. I've had the same with some other package and then I've found that the download was called something else than the package name after the installation. Perhaps the same problem? What is the package really called?

Mind you, I would actually prefer to get rid of the package anyway and have the device permanently locked in landscape but apt is telling me that it would render libcpaboutcssu, rtcom-accounts-voip-support, rtcom-messaging-ui-portrait, dsme-thermalobject-surface, modest-home-applet, qtquickcompat and maemo-optify-runonce candidates for autoremove. The ones I am not sure about are the ones in italics. What exactly do they do?