Another option, Steve, if the gap isn't too huge, is to run thinned white glue in there, until the gap is pretty well closed. Let it dry, wipe it smooth and clean up any overage with a damp q-tip.
Then paint, and when you're into the weathering stage, run a dark wash in there, just as if it were a panel line. Many wings were attached to the fuselage as a separate assembly, so there can be a seam there where they were attached on the prototype.
It's not always the right/best solution, but it has the advantage of preserving any detail near the wing root.
I did it with this Wildcat, and although part of the seam is concealed by the walkways, up near the nose the joint is no more evident than an engraved panel line.
Whatever you try, hope it works out for you.