Maybe finding a shot/frame with as many colors as possible (I like the falcon cockpit wide shots for this) from the print-based LDs, you could average/median them and see what results you get. Might help remove the inconsistencies.
I still think one of our scripting/programming geniuses should look into writing a mode average plugin for avisynth or matlab, as the most commonly occurring pixel is more likely to be correct as opposed to the one in the middle or a combination of those available.
I personally found, that the 1977 bootleg, from which I shared some screenshots, has consistent colors, that are in reasonable agreement with the frames I have and with the photos I have of the Mike Verta screening (7 or 8). Send me a PM for more details. 😉