Can you explain what you mean by
...the original assets outside of the program.
perhaps by providing an example?
Graphic files, audio files, video files, etc. They aren't available anywhere outside of the Director source code.
Did you look at the sharpexport?
I read about this some time ago when I was seeking a way to export W3D files from director and edit them.
I hope Adobe address this issue of editing cast members after being embedded, if you don’t have the original files it’s a pain.
Graphics can be exported using Valentin Schmidt's ImgXtra, Audio files using the AudioXtra, video files must already be external (the castMember is just a link to the file).