As of right now, we do not have any wheel opening moldings for the 63-66 Darts, but this is one thing Dave Layson does want to get reproduced at some time in the future.
As for the wheel opening moldings for a '65 Valiant, the moldings for the 64-66 Barracuda will fit just fine as they have the very same shape of openings as the Valiants do.