I have said it before on many occasions (but possible not here), that this colour combination is to me the classic Pelikan look - black and green striated barrel and gold trim.
This nib is not the best example of a Pelikan M600 medium nib that I own - I can't seem to see any fault with it when viewed via a loupe but it is just not smooth. After this rotation I might take to its tip with some micro mesh sandpaper to see if I can't improve its feel.
Air Corp Blue-Black was released in 2007 as an tribute to the Flying Tigers of 1940.
This ink is very dark, almost black. It is certainly not what I think of as Blue-Black by any stretch, if anything it has a green undertone. Nevertheless I like this ink and would happily use it day in, day out.