"Fan preservationists however can digitize the source material, and compress it so that it takes the WHOLE place of a DVD 9,minimizing compression artifacts and retaining as much information of the analogue source as piossible."
If there are compression artifacts from putting it on DVD-5, they are going to remain there if we put it on DVD-9. We can't "undo" the artifacts simply by "recompressing" the films, because too much material has already been lost due to lossy compression. In fact, we are more likely to add more compression artifacts in doing so, since the master file (the original MPEG), has already been compressed once. It would be like taking a 128kb MP3 and recompressing it to 256kb. It really isn't going to sound much better than the original. Now, if we had the original video, or for the sake of this analogy, the original CD, then a new file compressed to the higher bitrate will be of much better quality.