I've made some real progress on the wing, but I was still being held up by the sense of scale. It's hard enough building something that really only serves whatever purpose your mind gives it (is that a small motor or is that a battery?). But when you loose a sense of scale too, that's where the trouble starts to creep in.
To remedy this problem, I made a large piece of fruit; namely an orange. This would serve as scale as I designed, in fact you can just made it out near the center of the wing in the picture above.
Now with a sense of scale I could design things proportionately. It made sense to add in screws and bolts, or seams in the metal plating. But this also means I need to go back to the older sections of the model and update them with a higher level of detail- not a huge problem, but something further to do now.