Roland has made a start on the '66 Mustang Convertible rust repairs. Both sills are completely rusted out. And being a convertible, this means the car's structural integrity was seriously compromised. To compensate for having no roof, the sills in the convertible are reinforced in the factory. They comprise three separate panels...a flat, heavy gauge panel sandwiched between the standard outer sill panel and a U-shaped, heavy gauge inner support. The photos below show just how little steel was supporting the car. I will post further photos as Roland replaces the rusted sills.