Czech & Speake Dark Rose has been out of production longer than a year now. More like two to two and a half years. It's permanently discontinued as far as I know.
When Czech & Speake stopped having its fragrances made in Milan (2005) and moved the production of their fragrances to England (2006), the Italian company got to keep or refused to relinquish the formula to Dark Rose claiming it as their creation or something to that effect. If you have a bottle of Dark Rose, or even a decant, you're a very lucky person.
I am not an oud person, so it wouldn't be fair for me to comment on your question since as a non oud person none of the Montales appeal to me, but I will say that Czech & Speake Dark Rose is the only oud based fragrance I like and can wear. I predominantly think of it as rose fragrance, though.