British Film Inst put it on YouTube
9 minute (as much as possible!) version:
http://www.youtube.com/watch?v=zeIXfdogJbA
3 minute highlights:
http://www.youtube.com/watch?v=WQDyshif6v0
The movie obviously were influenced by the John Tenniel illustrations for the original "Alice" book. My favorite bit is the "Cheshire Cat" (just an ordinary film of a British housecat superimposed on the "Alice" film).