
Issued 19730402 to honor Nigeria's Argungu Fishing Festival.
https://en.wikipedia.org/wiki/Erhabor_Emokpae ... (designer) Erhabor Ogieva Emokpae, OON, (9 May 1934 – 16 February 1984) was a renowned Nigerian sculptor, muralist, graphic artist and painter who is regarded as one of the pioneers of modern arts in Nigeria.
My
guess is that this cover was put thru a mail-opening machine that took a sliver off of the top ... of the envelope
and the stamp ... but one can never rule-out a hand job.
According to the corner, Gulf Oil Company (Nigeria) Limited was the proud owner of Private Mail Bag 2469, which makes me wonder:
- how many private mail bags there were, or
- whether they just picked a number they liked, or
- if the bag was an upgrade for their once-regular box, or ???
Cheers,
/s/ ikeyPikey

Argungu Fishing Festival
Country: Nigeria
Catalog codes:
Michel NG 285 II Y
Stamp Number NG 303
Yvert et Tellier NG 293B
Stanley Gibbons NG 302
Issued on: 1973-04-02
Perforation: comb14
Printing: Offset lithography
Watermark: no watermark
Face value: 30 Nigerian kobo
NSP & M Co Ltd 6 mm long and ending under the "N" in ARGUNGU.