No one makes them and the Barracuda drops are not the same. I have been down this road with my 66. I bought a pair of nice ones from Desert Valley Auto parts. I don't know for sure but 63-66 should be the same.
If you are handy, you (or your body man) can fashion patches. I haven't seen photos of what you have but usually the lower few inches are rotted and you really don't need to replace the whole thing.
If you are looking for used pieces, start a parts wanted thread here on the site.