Wrote up a little decompressor for Midway/Atari N64 games. There's only two compression schemes they use, but the blasted things have no headers so you'll need to have preconstructed file lists to grab the resources. Still making up more lists, but have three games down so far. Gauntlet Legends was the only one nice enough to have a decompressed, verbose file list.
To run the script you'll need python 3.2 and tkinter 8.5. Oh, and your ROM should be unbyteswapped. Filelists are provided for the following games:
Rush 2049 (North America)
Rush 2 (North America)
Rush 2 (Europe)
Gauntlet Legends (North America)
Gauntlet Legends (Japan)
Gauntlet Legends (Europe)
Incidentally, also worked out the majority of Rush 2049's file structures. Might inflate into an editor or importer or something along those lines eventually.