Thank you Clemens
Step 10 - A "fun" part and so a long post. A very complex part with lots of angles has to be build with nothing then a single image in the instructions. Joke. No drawings, no angles, no marks and a f******* d**n instruction..
Unfortunately, there are virtually not much sources, especially when it comes to details. I have Marquardt's original plans, then there is a paper model with some pictures, a very well-built model with pictures but many differences in detail, and two small black-and-white images of Marquardt's construction (which also differs from his plans in some details). So there is a lot of room for interpretation.
First, I had to determine the total width of the object and exactly what needed to be removed from the bulwark (I have no idea why the 3D-printed cover wasn't adjusted accordingly already...).
The side wall was then sawn freehand along the markings.
Fits.
Continue customising, step by step.
Filling and sanding.
There wasn't enough wood at the front, so something had to be added.
Grind in the rounding (still needs more

)
Ready for airbrushing
Next step will be glueing the part, then filling and airbrushing again where needed.
cheers
Dirk