I reached out with this question to an acquaintance who's seen a lot more movies than I have, and he tentatively suggests that, left to right, the photos may show Fred Solm (1899-1982), Oscar Shaw (1887-1967), and Marion Davies (1897-1961). I'd never even heard of the first two actors, although Shaw was in the Marx Bros.' "Cocoanuts". Davies now is perhaps best known as the mistress of William Randolph Hearst, although she had a substantial silent film career. Unfortunately, the only film in which the three actors appeared together was the sound version of "Marianne" (1929), which doesn't quite fit your date range. I'm terrible with faces, so comparing your photos to others of those actors on Google isn't helping me. (My first guess for the fellow on the left was David Niven.)

-MTD/neb