Good news, we managed to upload all the old data we found, and I wrote a hacky script to turn the old NeHe ASP pages into html, and make all links point to the new file locations... Check out the "Legacy Articles" on the right hand side of http://nehe.gamedev.net/ !
This contains only the contests for now, NeHe's old downloads and projects have a different format so I'll write a script for those as well in the next days.
The text formatting might look weird at places and not all links will work (e.g. not everyone uploaded their source code), but as I said, this was just a hacky script
Have fun with the contest entries! Although I guess nowadays you should not code either C++ nor OpenGL in the way these guys did around 10 years ago