Hi Marco!
On my thread about the Mayflower I describe an
"old" technique how to make nice convex parts out of carton. Maybe this might be helpful for your build of the stern. I mentioned there to weaken the structure of the carton (1mm thick) with a knife. But I think in case of card it is as well as sanding after wards not necessary.
Anyway, looking forward to see more and a nice build so far!!
Regards,
Radek
__________________
On the Ocean:
Koga Elbląska,
Mayflower
On the Rollfield: Horten GO-229
In the Shipyard: Neptune, Een Hollandse Tweedekker
In the Garage: PANHARD AML20