Thank you for the covering fire Jack but the major thread drift was my fault.
Anyway by penance I have been doing some digging in the Gazette - Brakedwell do these dates seem right?
Appointment to a direct commission (scheme B). As Acting Pilot Officer from Cadet Pilot (twelve years on the active list and four years on the reserve)
18th Jan. 1956. period of service to count from 19th Oct. 1955
3521732 Christopher Robin BAKER
Acting Pilot Officer to Pilot Officer 18 Jan 1957
Assuming it is him, I can find no further references using his number including any to relinquishing his commission/retiring.