Replacement steel panels aren’t available, but repair sections are. Focus on the headlamp and indicator surrounds, front wing trailing edges, inner wheelarches and boot floor. The area where the fuel filler pipe enters the car is also vulnerable, especially on pre-1954 cars. The front wings bolt on, but a patch often gets welded into the inner wheelarch, attaching the wing to the main structure. Also check the A- and B-posts, where the doors attach; these rust, and while repair sections are available, fitting them isn’t easy.