Nice find! Maybe it could be improved by toning down those rather bright colours with thinned black paint run directly into the crevices, painting the cockpit struts, and adding some drybrushed smoke spots behind the exhausts and gun locations?
As for the pilot, very, nice work, but I think the jacket should be blue grey (at least for the Battle of Britain, if I'm not mistaken). But the face is superbly defined, yet smooth at the same time.
EDIT: Just saw that it's a late-war Spit, so the jacket comment above might not be correct.