This shows the basic outer and inner floor board pates for the Model B. The upper piece is the inner and holds the foam seal down in place around the pedals.
The lower flat plate is the outer plate, and it holds the rubber rebound bumpers which the pedals rest against.
The pic above shows three variations of inner plates. The upper has the brake pedal hole punched highest on the stamping. This is especially visible by referencing the position relative to the upper corner and stiffening bead.
The middle plate has the brake pedal hole lowered about 3/8 of an inch.
This bottom plate has the largest opening, and it is as high as the first, and as low as the second. The bottom plate appears to be a re-strike where the first style was struck again to remove more material out the bottom to be more like the second style. Variations never cease!
This view shows the same three plates stacked on top of each other. The last style with the re-strike brake pedal opening is on top in this view.