Bonjour, Jacqueline!
The programme used to be 15 minutes long, five days a week, is how I understood it and was condensed to an hour in the omnibus. I believe they deliberately recorded ‘fillers’ that could easily be removed. (Perhaps that was the origin of ‘change counting’ so beloved on the old BBC messageboard.) I suppose the removal of the opening music for all but the first episode and the closing music for all but the last would have helped cut it down.