Came across these photos of the Midway Drive-In, somewhere in Ohio. (My apologies to the photographer — not sure where I found these.)
It’s obvious how the owners handled to transition to CinemaScope — they simply added “wings” to either side of the screen tower. My guess is the extension would’ve happened in early ’54.
Imagine The Man From Laramie (1955) on such a screen on a nice night.