—Some evidence to support this theory—
No releases have been widescreen thus far but that doesn't necessarily mean it ain't so. Criterion released some movies open matte back on DVD but are now correctly matting them to widescreen.
There seem to be many films for the 50s that were once considered full screen but now are being released in widescreen since people are realizing that they were most likely shown that way in cinemas (examples. Creature from the Black Lagoon, Paths of Glory, The Killing, On the Waterfont, Anatomy of a Murder, Dial M for Murder, Psycho, and even Welles's Touch of Evil).
Arkadin was filmed in 1954 and released in 1955. Masked/flat widescreen (shot with film stock for the academy ratio but protected for a widescreen ratio) had already been introduced first in April 1953. While Arkadin was not a Hollywood production, I believe by 1955, European theaters had already switched over to the ratio.
I actually am posting this thread because I've just watched Arkadin (Confidential Report cut, to be exact) in a 1:66 aspect ratio on my TV. I don't claim to be a photographer, but the ratio seems to provide ample headroom in a lot of shots (even more so than usual, as is common in Welles's films) and eyes never seem to be too high in frame. The credits are also suitable for this ratio. The only issue was when Michael Redgrave was feeding his pet, it was barely in frame.
Now I'm not asking that any new releases of Arkadin be only widescreen. The best case scenario would be something like the Touch of Evil MoC BD that has both ratios.
That being said, if any of you have proof or theories to the contrary, I'd love to hear them.



