AT THE CIRCUS (1939, USA, 87m, U) ***½ Comedy, Musical dist. Metro-Goldwyn-Mayer (MGM); pr co. Metro-Goldwyn-Mayer (MGM); d. Edward Buzzell; w. Irving Brecher; pr. Mervyn LeRoy; ph. Leonard Smith (B&W | 1.37:1); m. Franz Waxman (uncredited); ed. William H. Terhune; ad. Cedric Gibbons. cast: Groucho Marx (Attorney Loophole), Chico Marx (Antonio), Harpo Marx (‘Punchy’), Kenny…