The plugin claims to do exactly what I need but is really out of date and hasn't been maintained for a long time.
I started off just trying to bug-fix a few issues, but as it ends up I've completely re-writing it to use custom post types etc.
I've not been able get in touch with the author - I've not had any response via the contact form in the plugin, and his contact details are a bit hard to track down.
(if you read this post please get in touch)
if I can ideally I'd like to release my code as an update to this plugin when I've finished.
If I can't I'll release as a separate plugin instead.