Original sentence: Because of the BBC's wiping policy of the era, of the 36 episodes made only 17 (of the original 23) episodes of the first two BBC series (1961–62) still exist in the BBC archives, all 13 episodes of the third (and final) BBC TV series (1963) and the 'Christmas Night with the Stars' sketch (1962) do not exist.Only 8 of the 10 existing episodes of the first BBC TV series, (broadcast in 1961), were released on DVD (DD Home Entertainment) in March 2006, the other two episodes (episodes 7 and 9 of series 1) were not included as DDHE
Edited sentence: Because of the BBC's wiping policy of the 1970s, of the 36 episodes made only 17 (of the original 23) episodes of the first two BBC series (1961–62) still exist in the BBC archives, all 13 episodes of the third (and final) BBC TV series (1963) and the 'Christmas Night with the Stars' sketch (1962) do not exist.Only 8 of the 10 existing episodes of the first BBC TV series, (broadcast in 1961), were released on DVD (DD Home Entertainment) in March 2006, the other two episodes (episodes 7 and 9 of series 1) were not included as DDHE thought the prints were of such poor quality.The film recording prints used are of a uniformly poor quality throughout this set