This FDC with a coin (COIN LETTER) is a rarity as seen on the picture of selling in the Netherlands in 1997, three years after the inauguration.
The translation of the advertisement is as follows:
THE INAUGURATION OF
The well known historic South African coin-letter brought out for the
event of the inauguration of Nelson
Mandela as president of South Africa. With
the special stamp, with the special first day
stamping and the special 5 Rand coin.
Collectors item and difficult to get.