Holy peppermint sticks! The title and the 1954 truck operators manual arrived this weekend. I can now affirmatively state that the model is 6103 w/body style TK. The truck owners manual explains the Shifting Two-Speed Rear Axle as follows:
"The vacuum shift makes this operation comparatively simple as it is unnecessary to declutch while shifting. The control lever for the vacuum shift is located below the instrument panel and to the right of the steering column. Turning this lever also shifts the speedometer adapter to maintain reasonably accurate speedometer and odometer reading regardless of the axle ratio used.
To shift from low speed to high speed, move control lever to high speed position as indicated on the instrument panel "DECAL," release accelerator, pause a second to allow engine speed to drop down, then again step down on the accelertator.
To shift from high speed to low speed, move control lever to low speed position, release accelerator and again step down on accelerator."
Thanks to everyone for your input.
