What are these two extra pedals on a '28 AA?

[seankerns]

I went today to look at a 1928 AA, it's an earlier one with a three speed and a lot of other early features. On the floor, to the left of the shifter, are two extra pedals that you can see here in this picture directly on the floor. These round buttons rock back-and-forth. When one is depressed, the other one comes up. I can't tell if it's meant to lock one way or the other or if there should be a spring that's missing. The current owner does not know what it's for. He hasn't owned the truck very long and hadn't even noticed those Pedals were down there until I asked him what they were. Is this some kind of an aftermarket over or under drive maybe? Thanks!

442011108_2608490285988687_6421494656934145704_n by SEAN Kerns, on Flickr

https://flic.kr/p/2pWyw3X

[rustya1928]

This is a dual high axillary transmission. Basically it is a direct and underdrive.

[emf]

Both pedals are connected to the same shaft. One pedal rotates the shaft clockwise, the other counter clockwise.

Frank

[Neil Wilson]

The dual high transmission was a Ford assembly line option. The shifter pedal is seen above the floor board (see attached drawing).