Tony Hancock was notoriously undisciplined about learning his lines and needed all the available rehearsal time to get them down. During preparation for "The Blood Donor" he was involved in a car accident and missed several days' rehearsal, but it was decided that the performance could go ahead if his lines were written out for him on "idiot boards" so that he could read them. His delivery remains as good as ever (reading the lines from a script was nothing new to him - having been on radio) but he is obviously always looking somewhere just off camera. He was so pleased to have found a way of not having to learn his lines that he continued to press to make further shows in the same way.
This series marked the end of the classic Hancock episodes. The subsequent series from ATV would never capture the same magic.
For this series, Hancock ditched his familiar and iconic wardrobe for something a bit more contemporary.
Among the various changes made for this final BBC TV series, Hancock's character was given a change of address in London. Whereas before he resided in East Cheam, this time he had a bedsit in Earl's Court.