Unknown lever - Cab 13

[Grant Bowker]

The attached photo was found on the "The Factory Photos" CD-ROM from Service Publications. From the surrounding photos showing a well used frame with an obviously new cab it might be a Chevrolet Cab 13 prototype. I'm not sure of the purpose of the lever that the arrow is pointing to. Another photo shows it as being close to the starter, so I wonder if it actuates the starter switch on the motor (either directly or via the bellhousing mounted system used by 11 and 12 Cabs). On the other hand, I'm used to seeing the Cab 13 starter lever coming up through the floor plate in the same area as the parking brake and working the starter via a rod to the switch on the motor. The offset in the lever arm makes me wonder if they still had too much interference with the parking brake lever and changed the design for production. Can anyone confirm, deny or provide other ideas?