http://www.youtube.com/watch?v=V2czfar4Zg4
Star with part 1 and move to the next ones, or, if you wanna be amazed, watch the last 2 parts.
The only difference from the version I've seen is the voice soundtrack for the last part.
Keep in mind two things: this version's voice soundtrack is from the mid 60s, the animation was done from the mid 60s to 1991 I think at a very slow pace due to the complexity, and there's 20 minutes of animation missing, filled with partial animation, tests, and story boards.
This is the american animation masterpiece lost forever due to ignorance and lack of vision from the producers and financers...