Diamond Dave had rear steer in his first buggy, Basically a Pump, Hand lever, and a piston to the rear axle.
He didn't have any way of telling when it was centred other than looking out at the back wheels. Someone else too a die cutter to a part of the piston that didn't go into the ram, and installed a reed switch to light up a "centered" light on the dash.
Pretty wizzy stuff if you ask me.