Mark, you said a while back:
This is the clincher for me, and I'm waiting to try out an integrated Alfresco repository to see if I can have content in Alfresco which is private from the outside world, but by virtue of the fact that an authorised user (teacher) has linked to it from a course then students can access it via Moodle. In other words, to the 'general public' the repository content is closed, but if you're coming in via your Moodle course then its open. This is how the Moodle 1.9/EQUELLA integration works, and it works well - if the Repository API doesn't support this kind of access then I need to do some serious rethinking...
How are you doing? Have you acheived this?