Thanks for looking in and commenting, Andreas, RAGIII, Gaz and Ondra!

I'm a bit further along now. The fuselage, which I thought would be the most complicated due to masking and painting the bands and wanting to tint the lozenge brown afterwards is actually coming along quite nicely I think, as this little dryfit with cowl panels and front radiator part shows:

(the nose panels are only in their basic paint coat so far and the white round access hatch needs a bit more trimming)
The lozenge wil be tinted more brown and I still need to think about weathering the whole thing to tie it more together, the contrast between the dark nose and lozenge and the bright red and white is a bit too strong for my taste

I gave the radiator a few dark washes earlier on and now glosscoated it again (together with the wings) and as I had the oil paints out anyway for weathering the lower wing similar to the lower fuselage under the lozenge I weatherd the radiator a bit to look like some pictures in the WNW instructions. As a final touch I'll add some gloss paints to some of the stains to make them look fresh.

It looks a bit stronger in the pictures than in real life due to the lighting -quite hard to photograph the effect.
Then there's the wings which I kind of underestimated I guess. After the complicated fuselage masking, decals, trimming, weathering, etc etc I though the wings would be somewhat easier, but I guess I took it a bit too easy. I trimmed the decals as per RB's advice, but somehow my glosscoat wasn't quite smooth enough and positioning the decals proved really tough. They're a bit misaligned on the front (blue rib tape) and especially the center part (which I did first) shows signs of silvering. I polished more for the rest so these are quite OK. I also had a few bubbles and wrinkles near the rib tapes.
On the other hand, learning this is best done by doing and making mistakes, so when I got to the wing tips I think I got the hang of it:

The silvering and bubbles are impossible to photograph, I'm hoping a satin coat (instead of the planned flat) will mask that a bit... The alternative is buying another sheet of wing lozenge and stripping it all off

On a more positive note, now that I know what went wrong, the upper bit as well as the entire lower wing will probably go a lot better!

Jeroen