Original sentence: It is believed that because these live performances was filmed (and later transferred to videotape for broadcast) most of this footage was preserved, despite the fact that many of the broadcast master tapes were later erased.It was thought for many years that most of the videotapes of the program had been erased during an ABC economy drive in the late 1970s, but recent discoveries at the ABC, notably during and after the closure of the old Gore Hill studio complex in Sydney, have revealed that much of the series was shot on film before being transferred to video.Recent estimates from the ABC indicate that as much as 90 percent the series has survived, although most of the first year of the show has been lost
Edited sentence: It is believed that because these live performances was filmed (and later transferred to videotape for broadcast) most of this important footage was luckily preserved, despite the fact that many of the broadcast master tapes were later erased.It was thought for many years that most of the videotapes of the program had been erased during an ill-advised ABC economy drive in the late 1970s, but recent discoveries at the ABC, notably during and after the closure of the old Gore Hill studio complex in Sydney, have revealed that (fortunately for posterity) much of the series was shot on film before being transferred to video -- including the unique live segments.Recent estimates from the ABC indicate that as much as 90 percent the series has survived, although sadly most of the first year of the show has been lost