Complex sentence: Copies from the original off-air recordings have been restored by Alan and Alys Hayes, and can be heard at their "The Avengers Declassified" website and its sister website "Avengers on the Radio".
Split into simpler sentences: Copies from the original off-air recordings have been restored by Alan and Alys Hayes. And can be heard at their "The Avengers Declassified" website and its sister website "Avengers on the Radio".