I agree that Wayback machine is your best path for recovering old user-written tutorials.
I recently reconstructed Jeff Cantin's splinesmanship tut from that.
If you know an old URL, it is a place to start. Note that the Wayback Machine may have archived a site many times, but not all of them may have the same resources (like JPGs, files to download, etc.)... so you have to check many of them.
Some may be incomplete in every instance.