Complex sentence: For a while, the theater was transformed into a strictly Spanish movie house, until 1973, when it was resold again and re-opened as a pornographic theater, initially showing "Deep Throat".
Split into simpler sentences: For a while, the theater was transformed into a strictly Spanish movie house, until 1973. In 1973 it was resold again and re-opened as a pornographic theater, initially showing "Deep Throat".