I created another, independent anchor point for the rear seat's shoulder straps, located at the junction of the tail post and upper longerons. This fitting has a loop of 1/16"" stainless steel cable in addition to that of the first anchor I built. It is secured to itself with 20 aluminum swaged fittings and two cable clamps.
I also set the bolts in place, securing the front seat harness' lap belt. I had previously coated the insides of all four holes in the lap belt attachment blocks with epoxy, and reamed them back out to size.