There is no Part 17 as the material is included in other parts. Once again, you will need to check out a modern map and guide book to be sure of being on the right tracks, if you plan to walk in this area.Here are a few links which will take you information about the area.
Office of Environment and Heritage:
Short video on Sassafras Gully: https://www.youtube.com/watch?v=8ToYouJtWJ4
Sassafras Gully 2012: https://www.youtube.com/watch?v=tp8JAlXKxn8