I think you are trying for two different effects. Paint is both worn and chipped. For worn paint, you nailed it right on at the wing root and around the canopy. But other areas look more worn, or even mottled, than chipped, and these are areas that will not see any use.
Paint on Japanese planes flaked off due to poor prep of the aluminum before painting, so the paint should look like it has peeled off. The best way is to do a base coat with enamel aluminum, then a top coat with the chosen color in an acrylic, then get a picture and chip and peel the paint in reference to the pic. I use toothpicks and a dental pick. You can still do this with you model by just applying the green and chip away.
Then do a wash of diluted charcoal or black to tone down the aluminum and make it blend.
Your doing a great job so far.
Scott