Peter,
I quite like #2 and #3. The angle you have on the bridge doesn't do it for me, not having the LHS pylon doesn't quite work.
Your rework for #2 is much better but I would also be tempted in bringing in a bit more detail in the middle part of the ship. I brought up the exposure a bit just for that section, a bit of contrast a bit less saturation and that made the ship that little bit more "obvious", for a lack of a better word. Similarly, on #3 I just selectively brighten up a bit a couple of the darker sections and that worked for me. I thought the trailing stars were a bit distracting, so cloned out the few you had there. Nice and quick, nothing much.
Hope I make sense
Cheers,
André