Screenshots for classic films with no blu-ray release

[theater dreamer]

Please forgive me if this has been previously addressed, gang. I searched on Google, and didn't find an answer.

I'm going to start working on our database again. My first goal is to make sure that every film that has been nominated for the Best Picture Academy Award has full information; these classic films deserve the same consideration that modern films get. Quite often, I come across movies that have no blu-ray release, yet they do have a background image. Cavalcade is one such example. In addition to the movie poster, which I already know how to upload, there is a series of screenshots from (I assume) the domestic DVD release.

What is the protocol for uploading images for these films that do not have a blu-ray release? Movies profiles for Top Hat, Libeled Lady, Shanghai Express, etc would benefit from at least one "screenshot" to give the main profile page a little more comprehensive look. Seeing that might entice somebody to check out the film. Are we allowed to upload an image from Google to serve as one screenshot if we don't have the DVD?

Thanks!