Wow, this was a hard-to-ptocess image. What can I say, I botched it while shooting. On the other hand, that’s the only exposure from that position and I want to keep it.
I didn’t want to rotate it too much, because I needed both sides. In the end I used Photoshop’s “Edit / Transform / Skew”. It took three attempts over the course of a few months, but now I am willing to accept it. It still looks wrong, but much less wrong 😃