In the 1950s began the oil history of Nigeria, attracting obviously oil companies from the industrialized countries.
For example, an employee of the French Régie autonome des pétroles received this mail posted in Lagos on 20 March 1964. The R.A.P., which dated and registered its incoming mail, was one of the three firms that gave birth in 1966 to what was known as Elf Aquitaine in 1976.
I like these little non-philatelic stories hidden in a cover found by chance in stamp dealers' cour des miracles box.
Without the proper catalogue, I just say that the stamp was issued after the Nigerian independence of 1960: no more a British royal effigy, insistance on the national territory (to instate its borders is a sign of sovereignty... and, today, those of Nigeria are still disputed: example of the Bakassi peninsula).
The cancellation bear a postal message: "Clear adressing / speeds your mail", that smells a British touch.