oyatz:
You are right.
The first two coins were minted in 1991, they were in paper currency forms before that year.
I remember buying an egg with three 10K coins in 1986.

In 1985, I used to buy 'Ewa agunyi' in Surulere, Lagos with 50k notes

You just brought memory of my childhood back!

I used to do it primary school.

ki02020:
I remember those days in school when we use pencil to trace the inscription on paper....a perfect black and white picture