That's interesting, never heard of it.  There are numerous photos of MT at
Oxford in 1907;  Michael Shelden mentions some things about that Pageant in
MT:Man in White.  Also on Barb's website:

http://www.twainquotes.com/19070628.html

I would love to see the film (if it actually does exist somewhere) uploaded
on-line, by some intrepid scholar/hobbyist... -hb