Thanks to Tom Sito for contributing the following information on Pepe Ruiz:
Yes, Pepe Ruiz was an important figure in NY animation. The Cuban born Ruiz 1914-1993, was an assistant animator at MGM in LA and he helped organize the successful union drive there in 1941. After 1943 he moved to NY when Guild President Eric Larson sent him to help the Famous Studios animators form a new local after returning from the Fleischers Miami sojourn. The union that had fought the FLeischer Strike in 1937 the CADU, had mostly broken up after the Fleischers moved their operations down south. Pepe was business agent during the bitter Terrytoons Strike of 1947, In 1952 when he saw how the Hollywood Guilds were being beaten up by the Hollywood Blacklist and a new set of hearings were set for New York, he merged his guiild into the umbrella IATSE, setting it up as MPSC 841. Pepe stayed the Business Agent of 841 until his retirement in 1968. In 1993 he was struck and killed by a car driven by R&B singer Wilson PIckett, who was DUI. Shamus had his own studio in 1948 and he regarded Pepe as a thorn in his side, so his diatribe in his memoirs.[*] He told me later he felt a little bad he was so hard on Pepe.
* Shamus Culhane's autobiography Talking Animals and Other People.