Yeah that's weird. DK was found in the 30's in SoCal right?
Same over here no nursery sells DK...but you already can find Hardy Chicago.
Fig enthusiast in Germany starting to talk about DK and some wise guys already got their hands on it ;-)
It might be the best fig to have inground in our region...
Of course you gotta protect the previous years wood. But that might not be a too big problem in mild south england.