Large promotional letter is 11x25" on stiff paper dated Sept. 15, 1937. Issued to promote the fact that RKO had taken over from United Artists as the distributor of Disney cartoons. Personalized to movie theater owner "Mr. Pratt." Top left corner has image of Mickey Mouse holding fountain pen as if he hand-wrote this letter. Text mentions the "First Picture Of The New Series" was "Pluto's Quinpuplets" and RKO's first Silly Symphony short would be "The Old Mill." Throughout the text Disney characters are mentioned and as such, their images appear along w/the text. This includes Minnie Mouse, Donald Duck, Pluto, Goofy, Horace Horsecollar, Clarabelle, The Big Bad Wolf and The Three Little Pigs, Clara Cluck, Judge Owl and Max Hare. RKO's distribution deal ran 1937-1956. Moderate wear/aging as originally folded. Left margin has .25" tears and a few tiny insect holes. VG/Fine. Rare.