I must admit, I never really saw a f2 black. The closest I could imagine is a f2 grey. I know that there are some relatively dark grey ones out there. But only cc himself can tell you if there really is one.
Why not hunt a normal depth black? In this case it should be even easier.
I wish you good luck for your search and post pics if you find one. 
Depth Black was my first skull
I'm lucky enough to have had a bunch of people help me assemble a nice little hoard of clacks that is beyond what I could have ever imagined after the bug bit me seeing Dan's OG Tri on his KMAC. I really shouldn't just be hunting for any more clacks, but this one would be near and dear to me for several reasons, plus the low probability of success means it will keep me from opening my wallet for a while.
This is an oddity and would complete a 5-piece set that I do not believe exists in complete form. EK sale says there were some, and there's Kisa's photo I added to the OP, but there is no other record of these keys except in Topre. I really like sets and matching pieces in any of my collections, so I would get great pleasure in getting the last piece of this particular puzzle.
Maybe I also like chasing ghosts
