Thought I would post an update to this thread. For those who would like to play it without having to compile it, Marc Suave, whose old Jedi Knight Editing Academy page is still up, has the Secret Level, and has replaced Dark Mara with Darth Vader, for those who would rather have Luke fight him. Here's the link to the level:
http://jediknight.net/editing/files/bespin-sev2.zip