The drawing of the turtle deck is not too clear. Luckily I have lots of photos of this airplane, and it soon became clear what the shape was like. There are 7 longerons in the turtle deck, and it has an elliptical shape at the front, and flat at the back.
I have tried to get the right shape for the turtle deck, but it just doesn’t look right. I’m not sure what the problem is, and I am having trouble getting the angles right. This is, unfortunately, what sometimes happen – It looked like it was going to be dead easy, and then it just doesn’t work out that way.