Q22.04. Class 08 13238 to D3238

Harris, in his book , The Allocation History of BR Diesels & Electrics quotes the renumbering date for Cl. 08 13238 being renumbered to D3238 as 30th August 1963. This seems extremely late with most of the class being dealt with in the 1950s. Can anyone advise if this is correct or quote earlier dates from their records? The loco was allocated to York throughout the renumbering window. (Paul Chancellor: 9408)