I can't take you all the way because I'm new to the format but hopefully point you in the right direction. Contained on the disk as well as those files are two text files which are manifests. One points to the 99's, the other singles out the 10's as game levels. You won't get anywhere trying to open one however because these files are split, think like a "rar" or "iso" in several pieces that needs to be joined to be extracted. They may also suffer a special compression given the disks format is WBFS? Anyways search about online for split files of these types and how to join and use them, there seems to be a bit out there though lengthy.
Would the text files by any chance be cdgame.txt and levels.txt?
I'll keep searching around to see if I can find anything. I wish I could upload all of them so someone could help me further, but then that'd be considered piracy.
Thanks for your help!
Still open to further suggestions if anyone's got any.