Cropped from a horizontal frame, I had tracked these two in and of course just as they turned a number of additional birds going the other way got behind them (oof) so I cloned them out.
Nikon D300a, 600VR, TC14EII, ISO 400, f7.1, 1/2000 CW metering, +1 EV
Great synchronized flight positions, and excellent head angles on both birds. Is this a molting plumage? On my screen there seems to be some noise evident on the underwings.
You did well to get two of them syncronized, in focus, and in a pleasing position. It does seem to be lacking some detail. This is probably due to either the fog, or a large crop, or both.