Back to the Caribbean!
This cover was sent by Cpl EF Kinmond, RAF Transport Command, based in Trinidad to who I assume to be his brother, Cpl JD Kinmond at 38 SFTS, Estevan, Saskatchewan.
I note that they have consecutive service numbers, which suggests they joined up at the same time. In fact, FWR says they both enlisted as pilots in the RAF Volunteer Reserve in January 1937.