Thanks, RB, Manni and Gaz!

The oil staining is actually a mixture of Raw Umber and Payne's grey, an almost black grey colour. I simply apply a few dabs with a toothpick and smear, smudge and mess it up with a short haired (cut off) brush and some sponge. Then I add a bit of clean thinner and just let it flow, then clean up some off the excess.
Honestly it was about 10 minutes work... the splatters were thinner dirtied up with the paint mixture in a brush and then simply blowing my airbrush (without paint, obviously!) through the brush. This creates a nice splatter pattern.
I actually could have made it a bit heavier, as it does not show up all that well. Part of the learning curve I guess!

In the meantime I added some Lozenge decals. As RB indicated the Aviattic wing decals are slightly too wide so they eventually misalign a bit with the rib tapes on the model, perhaps not as noticable with lozenge tapes, but all the more with those blue ones. I did the center part first after checking its fitting, then I tried the left and right bits with the cut-out for the ailerons and found as RB indicated I need to take about 0,5mm off for a perfect alignment. There are a few bubbles and wrinkles -again part of the learning curve, but the bubbles will be taken care of later.

The fuselage sides were drawn over from a photocopy of the WNW decals and carefully trimmed to align with the red bands. The small upper part with the cockpit cutout was the single most hard part of the whole decal process -took me 3 tries to get a part with everything lined up and not showing any white. With hindsight I should have cut this in 2 or even 3 sections applied individually, as I have a tiny bit of overlap on the fuselage spine on the red. Perhaps only 0,3mm, but it does show op. Again, part of the learning process I guess, and a bit of weathering will hopefully camouflage it a bit!

Don't get me wrong though, I'm my own worst critic, but I'm loving where this is going!

Next up is the fuselage bottom, then masking off the red again for some brown tinted overspray after a few bubbles and cuts have been made around the access panels.
Jeroen