John, this is John....
I think the T-tank was bolted to the floor - I don't remember any tie-downs. It was made of a heavy black plastic. I think the fuel connection was on the right side (looking forward) and connected in somewhere close to where the a/c's own fuel filler neck was. I have a Robertson diagram somewhere but don't know where it is - it's buried deep in a box.
I can't help you with any radio gear info in the rear compartment. I have no details.
As far as seats, they used the standard OH-6 mesh seat. I have never seen a photo of an AH-6C with any armor fitted but that doesn't mean they didn't use it. I know that the AH-6J could use an underseat armor plate. A pilot for the 160th told me they didn't use side armor, that was circa 1998.
On ARC some of the postings had to do with gunsights. I've been told the 160th used grease pencil marks on the w/s. They later developed a laser pointer.
As far as the ARC photos of the AH-6Js with the side scoop, I knew that existed but have never seen a photo of it. The first I ever saw of this was an AH-6J displayed publicly at one of the Andrews AFB air shows about 10 years ago. That aircraft had the opening with the mesh screen and there were places where something could mount. The crewchief told me this was an oil-cooling device. I've also seen photos of the opening with perferated holes, not a mesh.
As far as the flange on the exhaust system, I believe that is what the seldom-seen IR-reducing "sugar scoop" exhaust attaches to. The other option was to use the tailcone, and have the exhaust go out the sides.
General comment on those photos - they are old. Looks like they date to the early '90s. The a/c have the old batwing SATCOM which was later replaced by the x-wing. They also have the longer plank fitted. These a/c also have lots of staining from minigun blast. Interestingly some of them have the fast-rope attachment fittings around the rear doors, indicating they could be used as either an AH-6J or as an MH-6J.
John Hairell (tpn18@yahoo.com)