I didn't know that the Gaiam Fleischer Superman BD was such a hopeless mess.
http://www.blu-ray.com/movies/Max-Fleischers-Superman-Blu-ray/50279/
http://www.arthousecowboy.com/journal/2013/5/8/do-not-buy-gaiams-max-fleischers-superman-blu-ray.html
It looks like there are some 1080p up-scales on youtube.
https://www.youtube.com/watch?v=9UJphNPwDfk
Perhaps, up-scaling the DVD video with Video Enhancer (Super Resolution) and then using some sort of dust / scratch removal software, like Neat Video, might be an option for restoration?