Unconscious ‘tuts’ only appear in the first half of his act and are usually preceded by a very short pause and followed by ‘and’ or ‘er(m).’ They may just be used as fillers for time or while he thinks out his next sentence, but there is evidence to suggest that they are possibly mnemonic reminders.
(B,8-12) "(.) My mother-in-law drives, but she hasn’t passed her test (.H) (T) erm (.) and she’s been driving since before the war (.) (T) and I think she’s gone through twenty three tests or something such. Almost an all time record for Warwickshire."
(C,8-12) "(.) (T) erm. Actually my mother-in-law has been driving since before the war (.) right (T) and she has still to pass her test (1) (T) and, er, this is a fact, she has some record of the tests taken in Warwickshire or something like that."
The tenuous analogy I can see runs thus:
TEST — WAR-WICK-SHIRE
So, in the first version ‘test’ recalls ‘driving before the war’ and ‘war’ prompts her record for the number of driving tests taken in Warwickshire.
In the later version ‘driving since before the war’ recalls not having passed her test and this prompts her record of the tests taken in Warwickshire.
However, there are no further comparative examples in these two transcripts, so no concrete conclusions can be drawn from this theory at present.