Hi all,
I think the 3D printed panels could be enhanced with a bit of fine scribing.
Also the Fokker style panel nuts could be replace with those from 'Taurus Models' (3224).
http://www.taurusmodels.pl/The louvres either could be drilled out or removed completely and replaced with louvres stamped out using a die set from 'Flugzeuwerke'.
https://www.shapeways.com/shops/flugzeugwerkeActually, with all of the above you could more or less scratch a set of panels.
Either way, a lot of work and expense to achieve anything that's up to the standard of the WNW panels,
Mike