Might be a regional issue... I had to have a West Coast friend order something that was out of stock on the East Coast, and have it shipped to me. That might answer why something is showing out of stock for one person but not for another?
As for the Casablanca Twist... order a 4 oz. tin of Darjeeling 1 or 2, or Spring Darjeeling, or Nepal 1st flush... and a sample size each of peppermint and spearmint... and blend away. It will be fabulous.
I love mint with Darjeeling far more than with the traditional gunpowder green found in Morrocan Mint... and that's what Casablanca Twist is... darjeeling and mint. Just play around and find your preferred parameters.