Hi Stephen, sorry for the late response. We are about to implement a machanism that allows users to always get "the latest" set of introductory notebooks. That being said, this set will change and evolve from time to time. So it's always a good idea to make a copy first before hacking.
Please have a look at the current set of notebooks on our website:
http://datalab.noao.edu/notebooks/web/
I hope that some of the examples you use are in there.
Robert