George Pal's John Carter of Mars?

I'll cut to the chase. I got the recent issue of Filmfax magazine, which has been running their own centennial celebration of  Edgar Rice Burroughs. Inside what caught my eye was a letter on the editor's page from reader Bob Statzer that mentioned that after Ray Harryhausen had passed on making a John Carter of Mars movie that producer George Pal (best remembered for his 1950s and 60s sci-fi classics like The War of the Worlds and The Time Machine) and stop motion artist Jim Danforth (who had worked with Pal) had approached MGM about making their own John Carter film. I had never heard this before so I did some Googling and found a discussion on the Classic Horror Film Board, http://monsterkidclassichorrorforum.yuku.com/topic/5363/JOHN-CARTER-OF-MARS?page=4 that mentioned that Danforth had created 16 mm test footage for the project. Has anyone ever seen this footage or heard anything else about this project? It provides an intriguing footnote to the history of John Carter on film and it might be worth seeing investigated.