Complex sentence: Studio records indicate that the negative of filmography pre- 1931 was marked "Junked 12/27/48" (December 27,1948) or in February 1956, Jack Warner sold the rights to all of his pre-December 1949 films to Associated Artists Productions.
Split into simpler sentences: Studio records indicate that the negative of filmography pre- 1931 was marked "Junked 12/27/48" (December 27,1948). In February 1956, Jack Warner sold the rights to all of his pre-December 1949 films to Associated Artists Productions.