I've had another few thoughts. I can't really explain the positions so I did a little editing myself

:

The area of ground just underneath the aircraft, in front of the tail wheel which I have circled in red. There seems to be a 'dip' in the ground, and as the rest seems perfectly flat, this suggests an edit.
The area at the bottom left looks odd. I think it's because it looks very 'perfect' compared to the ground next to it. I think there was something there that has been covered up.
Jon
