The back cushion has two brackets that slip into openings on the cab back wall to hold it in place.
The 1939-46 design gives a totally different way the lower cushion adjusts. It sits on four front to back braces above the gas tank. Two of these braces have small pegs which fit into holes in the cushion bottom. In this way, the cushion can be lifted at the front and moved forward or backward.
NOTE: The lower and upper cushions connect where they meet. Thus, at least the lower part of the back will move with the lower cushion. Unfortunately, your shoulders and arms will always be the same distance from the steering wheel.
Harold
Last edited by Harold46; 04/25/2017 5:22 AM.