Did you check with engine running?
Wire 5200 on 716-11 is my constant 12 V
I can´t help you with the 3185/3187 problem as it does not seem to be same diagram as I have,
(on mine 3185 stay at 0 volt because it does not have any pin at the back of column autosteer switch, and 3187 get 12/13 V when autosteer switch at column is on)
I do NOT have the button at armrest, like you and fivefinnishfarmer have.
It is A0 on PCB (arduino A0) for 3160
The other wires you also have correct.
In the Manual.pdf around page 14, you see where to set psi for pressure cut off.
Did you find this thread ? Case IH Puma 230, autosteer ready - #12 by CVX