These are still standard def but on Bluray for max quality - Bluray discs do not play on standard dvd players.

The episodes are as shown on the discs. 

Xmas Day 1969 is a partial of only about  15 minutes.

The 1968 and 1971 editions have mute links. 

27/12/73 is the 10 years celebration although at 35 minutes there is roughly 10 minutes missing.

August 1974 is the legendary edition co-hosted by The Osmonds during their week long series of 6pm live concerts on BBC1.

Some episodes are from unedited studio recordings complete with delays , mistakes and retakes.