Mustang floor pans, mustang cowl repair panels, and there are a couple of places you can buy quarter panels. I know rock auto has them $$$.
Virtually nothing is made for a Maverick, and what is made is not an exact fit/replacement. That is why I recommend buying the most rust free car you can find. Fix THIS not THAT: http://mmb.maverick.to/showthread.php?t=86787&highlight=fix