Triumph TR6 Floor Panels
Confusion often arises over identification of the Inner Sills (907912/564807). The Inner Sill is positioned INSIDE the car, between the floor panel (904005/6) and the UPPER part of the Outer Sill (850281/850282).
The section that often rusts on the UNDERSIDE of the car is in fact part of the floor pan. Unless you anticipate replacing the whole floor, the rusted section can often be repaired by using standard sheet steel cut to size.