31 PA Gas Pedal original or "optional" ?

[FourDoor]

The screw-on round disk is the original gas pedal. Any rubber pedals were aftermarket add ons. Your foot could slip off the disk if the bottom of your shoe was wet so the rubber pedal was an improvement but is not authentic for a restoration. 

[BryanD]

My recently acquired 1931 PA came with no gas pedal, just a shiny dome-shaped "button" maybe 2.5" in diameter.  I have been assuming that this was "stock" for this model.  However, I now see that a replacement pedal (long black rubber type) is available for this model.  Can anyone confirm that a long black gas pedal was stock on this model?