I control a 1903 with DC + an Integra.  Do you have pneumatic valves?  Your setup looks a little different than mine, but you should have air solenoids somewhere in the cab to wire into.  I have left and right pneumatic butterfly valves, but they are controlled by hand levers, so I had to use an air activated switch that goes to the master wire.  I also have 5 air solenoids for the 5 sections on the boom.  I just wired directly to the solenoids in the cab, before the toggle switches.  I am using a liquid control module and an aux input module.  I am also using a raven harness adapter that plugs into the modules.