Yes, one is missing.
But, there is included one card "extra". Read the description.
This extra card is a series I card, since it has only one trim pot. It is the most left card in the spare parts picture. The series II/IIX cards have got 7 pots.
I like the series I cards, they have a more crunchy sound and I got my private IIX equipped with 8 of them. Sounds great! :-)
Alexander