Cinematical has unearthed some fascinating correspondence from the 1940s between Warner Brothers and Groucho Marx. The cigar-chomping comic legend and his brothers were preparing a comedy titled A Night in Casablanca, which was an obvious attempt to cash in on the recent Oscar-winning Best Picture. He received a letter from lawyers at Warner Brothers that indicated the studio was concerned about the Marx Brothers appropriating elements of the story. Groucho uses the implied legal threat to his advantage, sending the studio a letter in which he states that even if Warner Brothers intended to reissue Casablanca, audiences would be able to tell the difference between Harpo and Ingrid Bergman. Click here to read his hilarious original letter.