Life imitates art
If indeed there is only one surviving, hissy and scratchy print of this film, then this exactly imitates the end of the movie, where only one scratched film recording exists of its once mighty protagonist. In the film his history is erased because he has turned against the establishment that used him and was deemed a subversive. Which seems to have been the fate of one of the most important and subversive movies of the 1960s.
If you seriously want to understand what the 60s was about, not the woodstock nostalgia 60s, you need to see this movie. But alas that 60s is being quickly erased from memory.