For those interested in such stuff, the two earliest Oz movies (1910 and 1914) have just become available for free download from the Internet Archive. They're both shorts (13 mins and 39 mins), and I confess I hadn't remembered the latter's existence!
Ain't this technological progress biz a wunnerful thing? When I was working on the movie entries for The Encyclopedia of Fantasy, it was my perfectly reasonable assumption that I'd never actually see the 1910 Wizard of Oz; now, just a decade or so later, I can download it for free in a matter of a minute or so and watch it on my puter screen.