Looks like it's getting there. Before you go any further, check the wing dihedral - you might find the gap will be smaller, or disappear, once the dihedral is at the correct angle. Also, that gap on the underside, inboard, might be the line of the split flap and radiator - bit hard to tell without actually seeing the model.
You should end up with a fairly narrow gap, if any, on the upper surafce joint. As Andy said, a strip of plastic card will fill that. Just insert, fix with liquid poly cement, and trim off flush, or alternatively, use a bead of either CA glue or PVA.
NOTE:- Check reference pics for the upper-section of the inboard flap/radiator to get the angle correct - they didn't 'droop' as the lower half did.