Oops...I was just reading a manual from a British Oxford carrier! Same general idea as the Ford type, but bigger, fatter, and front wheel drive/rear engine using a Cadillac flathead V8! That stuck in my head.
But normal Ford carriers in the manuals and picture books I have all have the steering box with wheel working through the weird cam down in the floor...turning wheel a bit warps the treads by shoving over the middle suspension units, then continued wheel turning moves cam sorta thing more and it actuates the mechanical brake on one side or the other of the drive axle to force a sharper turn. Strange and interesting system obviously built on a budget. I have a diagram somewhere in a manual from an Australian built carrier, but I think all or most versions used this system...?