Meh, if you have no ATV, just look for a deal on the current ATV

Cinderella (1950) - Technical specifications - IMDb

https://www.imdb.com/title/tt0042332/technical/

Aspect ratio 1.37:1

1.37:1 (Academy ratio).

Only slightly wider than the 4:3 ratio used throughout the silent film era, the Academy Ratio was the standard film ratio in 1932 when “talkies” (aka, films with sound) began.

I’ve felt that for things linked with my Movies Anywhere account, that iTunes/Apple has a higher quality but I have nothing to back that up.