Tim,
How did your backhoe attach before the front remote?
I'm currently working a "front remote" or third funtion for my FEL also. Very similar to yours, but with a different valve.
The line now coming from the FEL joystick valve, port marked "PB" (power beyond), is now the pressure going to your third function valve. Port probably marked "P" (pressure). Most third function valves don't have PB ports. So the outlet of the third function valve will be 'R" (return) or "T" (tank) this will feed the next valve in line in a open center hydraulic system. Which will be the inlet of the hydraulic block pressurizing the remotes and the 3 pont hitch.
I believe what needs to happen is the line going from your "front remote" back to the hydraulic module block needs a quick connect in it to attach to the backhoe. That's how mine will be plumbed.
Good Pics....
What kind of switch are you using to control the 'front remote" third function valve.
Hope this helps.