I have a theory, that FC-20 is in fact the J-20.
Superficially, they all have the number 20 in their designations, which might indicate some kind of connection.
Logically, assuming the rumours that J-10B is used as a testbed for many 5th gen. technologies is true, then J-10B technology is...
I have a class-mate who came here when Yugoslave was still intact. I guess then he can rightfully say that he came from Yugoslavia or something in that line, too lazy to check.
Have you ever consider the possibility that the vertical stabiliser is not in its neutral position and that it's turned away from us thus showing more of its side to us. This would also explain the gap between the bottom front of the stabiliser and its base.