I'm a bit wary but may change my mind later. I'm thinking this situation is one-of-a-kind. I also hate the general .course accessor as what's returned is not a course but a course number. .course_id, otoh, is a longer description (full path e.g. edu.mit.eecs.6002x). In this case, we probably also want the run which in the new system is either part of the course_id or is the course_id + version depending on what pattern we adopt.