Not sure if any of this will answer your question, but I took some pics of a TCCCS RT-522 Installation installed in a G-Wagon. Its a Single IKEE, but really, other than a Second Radio and AMU, the install parts are essentially the same.
One can surmise that in all reality, the electronic parts should have been the same in an Iltis, and really, the install itself should have been very similar. Keep in mind, the G-Wagon is a fully enclosed "hard top" vehicle, so by rights, any Comms related "Ports" that need to be hard mounted outside will have been done to it.
Rad A installed in Doghouse with the NAU mounted on top. I'll ask one of the TCCCS literate guys what the "V1" Port is for as it is 1.5" OD. I suspect it is for an Amp:
I may copy the way these are locked on my own Radios:
Radio Interface Panel with Power Switch. Kinda like a uber-modern version of the old Bendix Connection. Don't get excited, those plugs are all only 1.25" OD
:
Control Indicator or "CI" mounted on the Dash, you can also see the new DAGR GPS Holder over on the A Pillar:
Another angle on the CI:
AMU on the Back Corner:
New Style Single Pin Slave Cable Outlet:
Lastly, for those of you guys who like to stencil stuff, there is an example of how the vehicle tools are marked (notice that the numbers don't match, and the neither are the same as the CFR on the truck
):
Again, not sure if any of this helps in your quest, but as you can see, there aren't really any 2" Plugs on any of the TCCCS kit that go to the outside of the vehicle.