I seriously doubt that one I one hundred people would know exactly what that trim looks like on a '59 Mercury.So why not replace both sides with identical ribbing that is as close as you can find and No one will notice unless you point but out(nd why would you want do that!).next best bet would either find a glue bomb '59 with good ribbing and either swap the panels or make mold from the good ribbing,cast them and swap those in.