Indeed!
It took several attempts to know what to do to accurize the shape. The result will not be 100% screen-accurate, however, that is not the goal. Getting the model screen-accurate woud require a complete remake since there are so many inaccuracies like the panel lines and missing pieces. The marvellous texture saves the model and justifies the upgrade. I really did not believe that it would require so much work in the end and I hope to get it ready in five days because that is when my deadline ends.
So now. To determine a different shape in three dimensions without computer support is a bit tricky. I found it easy to use several strips of paper with pointy edges.
I put the pointy edge into a corner, add another piece, tape the two together and work my way up.
A few parts later I realized that the shape can be simplified further, so I came up with this:
Taped together it looks like a little bird:
Now the shape is scanned and turned into the first upgrade piece for the bottom.