Well this certainly changes things. Wife says ratchet strapping a child seat to the floor isn't acceptable so I had to come up with a better solution for a back seat.
Busted out the sawzall and cut the old fairly useless island/table thing out and walled up the sides with 1/4 ply wrapped in the same carpet.
Picked up the narrow transit 2 person. Integrated belts and child seat anchors. Recessed the tracks down into the 3/4 floor plate. On the front 2 mounting bolts I was able to pick up the factory ribbing in the body just like the original chateau seats were attached, But along the back 2, I made up a 1/8" thick steel plate that bridges the 2 back mounting bolts so the nuts wouldn't pull through the floor in case of accident
Obsoleted one of the drawers, still haven't figured out what to do with it. 5'3" wife for scale.