I have the same joystick, and it is an elegant solution. The only functional drawback is that it can only move in one direction at a time -- ie: you cannot rotate and change the deflection simultaneously.
and that little joystick will do it all.
Unfortunately it will not do it all by itself. It has 4 SPST (Single Pole, Single Throw) switches, one for each position. It would have to have 4 SPDT (Single Pole, Double Throw) switches to be a stand-alone control.
The simplest solution is to incorporate 4 SPDT (ie: 5 pin) automotive relays into the circuit, one for each switch in the joystick assembly. Connect terminal 85 of each relay to a fused +12V supply. Connect terminal 86 of each relay to one terminal of the respective joystick switch. Connect the other terminal of the joystick switch to chassis ground.
Connect terminal 30 of each relay to a motor lead in pairs. That is, joystick left relay terminal 30 to one wire of the rotator motor. Joystick right relay terminal 30 to the other wire of the rotator motor. Similarly, Joystick up relay terminal 30 to one wire of the linear actuator and joystick down relay terminal 30 to the other wire of the linear actuator. (if the motor turns the wrong way when you activate the joystick, simply swap the two motor leads.)
Finally, connect terminal 87a of all 4 relays to chassis ground and connect terminal 87 of all 4 relays to a fused +12v supply.
So the way it works is that all leads of both motors are grounded until the joystick is moved. When the joystick is moved, the switch closes activating the respective relay, which then opens 87a and closes 87 to switch +12v into one motor lead.
A note on direction: When I wired mine on my rear-mount blower, I mounted the joystick horizontally and wired it so that pushing the joystick down depresses the chute, up raises the chute, to the tractor's left rotates the chute to the tractor's left (ie: CW) and to the tractor's right rotates to the tractor's right (ie: CCW).
It turns out in operation that is not intuitive (for me, anyway). I guess moving the joystick left pivots the lever clockwise and I kept instinctively moving the joystick that way whenever I wanted to rotate the chute clockwise. Similarly, pulling down on the lever is the motion one makes when raising the FEL arms and is the instinctive motion to raise the deflector.