First, anything 95 years old is in the public domain. On Jan. 1st every year, works created 95 years ago enter the public domain. As I write this in 2025, everything published ANYTIME during 1929 is in the PD.

Second, I like to read articles on publicdomainreview.org.

One thing you can try is to upload the movie to YouTube. But I’ve found that their detector is too sensitive, it’ll flag something undoubtedly in the PD as being under copyright.