Aren't we LONG overdue to have their codes released on the variants page?
They no longer do codes, as Apple has declared codes a blasphemy to the Laws of the App Store. It has been replaced with an ‘Unlock’ button.
Handelabra puts it more succinctly in this blog post:
There are no codes anymore, just a button to press. Is the button not there in the game?
The unlock buttons for those variants were made available on Christmas Day.
Doh, I remember all that now!