Well after touching up the few spots on the wing where there were noticeable joins in the decals, I decided the touchups were too noticeable. So I decided to add some oil paint streaking to cover these and pull everything together. I spent many a happy hour looking at all the pictures of EV wing streaking I could find and decided they varied from almost opaque to quite highly streaked, sometimes with no "segmentation" of the different colours obvious, through to clearly segmented with very little streaking showing. The Achim Engels EV reproduction shows very little evidence of streaking. So I decided to go for a subtle streaking effect to keep the lovely panelling in the decals still visible but to hopefully cover up the acrylic touchups.
I broke out the oil paints and after a lot of colour mixing I set to work. Here's the palette set up for the greeny-blue:

I applied the oil paint in uneven streaks and then worked it out with a blending brush lightly moistened with white spirit. Here's a closeup - the blue segment to the right has been fully brushed out while on the left hand blue segment the oil paint has been applied but not yet brushed out (I haven't done anything on the pinky-red area yet):

The effect is quite subtle (it's a little more obvious in real life) but works well. It hides any touch ups and just gives a slightly more streaky finish without hiding the lovely detail in the decals.