Complex sentence: It has never been released as a "legal" home video release: the original running time was 90min, when Universal Studios bought the television rights in the late 1950s it was cut to 77 minutes.
Split into simpler sentences: It has never been released as a "legal" home video release. The original running time was 90min; when Universal Studios bought the television rights in the late 1950s, it was cut to 77 minutes.