The first signature looks like Barbara and the second Arline. The photographer of the last photo, Maurice Seymour, was actually two brothers from Russia who resided in Chicago, taking photos of mostly theatrical, vaudeville, and dance entertainers in the area, and the odd celebrity who came through. They did really interesting work.
Can't tell who the guys flanking Laughton are, but the man in the bow tie looks very familiar. This is signed to one Rutgers Neilson, who appears to have been in publicity for RKO for many years. The man in the background, upper left, is (I think) George Marshall.
Thank you very much for the PM. I'm certain now that the man on the left (foreground) is RKO president George Schaefer, and that the year is 1939. Still puzzling over the guy on the right, but I do know he has wretched penmanship.
I think the hat goes back to the experimental aviation section of the prop department. It was later refined into a comic hat that barely lifted off the head then immediately lost altitude and came back down, which was popularized by Joe Penner.