He was a police officer (a reserved occupation) with Midlothian Police at the start of WW2. In 1941 some police officers (including Jock) were released as potential RAF aircrew. He completed basic training in South Africa under the Empire scheme and was kept there for another three years as an instructor. He came back to the UK in 1945 and had started operational training when the war ended.
He stayed on with a permanent commission and in 1946 he joined 612 City of Aberdeen Auxiliary Squadron as training officer. In 1949 when it was disbanded he moved to what was described as an instrument training squadron at Birmingham and after two years was posted to Jordan as Officer Commanding the Arab Legion Air Force (later the Royal Jordanian Air Force).
This is taken from an interview with him at the time of his appointment as CFI at Edinburgh. Without implying any disrespect it does not sound a particularly distinguished career but maybe it was for the time or maybe he was just in the right place at the right time.
ALW