Dear colleagues,
Thanks for the feedback and the advice!
ALBATROS 1234, I'm starting to think you are wright. It is indeed becoming and endless game of filling, sanding, filling, sanding,... Have to continue though as too much time already went in it. But if I should need to scratch new wings once again, Im sure I'll try 'the boiling water' method!
And now for something completely different: naval lozenge. I read in the Mini Datafile that in an early stage the naval lozenge was painted on instead of using printed fabric. As I'm building an early batch version, painted lozenge it will be. I suppose the paints will have suffered a lot from the salt water resulting in an uneven coverage of the paints after a while. Trying to achieve that effect, I did a little experiment on the canvas (I assume) installed behind the pilot seat.
Building the canvas with the tin foil...

Airbrushing with Tamiy Acrylic browns...

Adding the naval lozenge colors, with the aid of masks cut from Tamiya tape, using pastels. The Wingnut Wings Hansa-Brandenburg W.29 decals served as a template...

Conclusion:
1. Brown is not the good primer color as it changes the color of the pastel used. I'll try white primer the next time.
2. Definitely need to find the correct pastel colors overall...
However, going into the right direction and having some potential I think.
Till next time,
Dagmar