Anthony Barber was the outgoing chancellor in 1974 (not 1964). Reginald Maudling was the outgoing chancellor in 1964 and he didn't leave a note;
Hansard 1997
I cite the autobiography of my noble friend Lord Callaghan of Cardiff. Writing about the first day that he was in office as Chancellor, he says:
"I was sitting at what had been Reggie Maudling's desk in the ground-floor study at 11 Downing Street. While I was reading the briefs which Treasury officials had prepared against the possibility of a Labour victory, he was in the upstairs flat with his wife, packing their belongings. On his way out, he put his head round the door, carrying a pile of suits over his arm. His comment was typical: 'Sorry, old cock, to leave it in this shape. I suggested to Alec this morning that perhaps we should put up the bank rate but he thought that he ought to leave it all to you."
https://publications.parliament.uk/pa/ld199798/ldhansrd/vo970514/text/70514-02.htm
Alistair Darling was the outgoing chancellor in 2010 - he didn't leave a note either - it was Liam Byrne. All this talk of tradition is nonsense as far as I can see. Why hasn't anyone compiled a book of notes?