Another photo I have in my collection is the Marx Bros. for “A Day at the Races”. The film was released in theaters back in 1937 and starred Groucho, Harpo and Chico Marx . I’m not sure if this is actually a still or promotional shot from that film but a friend was able to see the picture and quickly identified it.  If that is the case, the other two are Maureen O’Sullivan and Allan Jones.
Back in 1937-1938, MGM did many horse racing films and this was one of them.