Getting the seat skin to release along the bottom was very difficult. The loops that cover the pivot were not much fun, either.

So, once I got the seat cover loosened up, I was able to slide it up and see the release mechanism. At first, I could see no problems. The mechanism was moving just fine. However, I lifted the cover a bit more and saw the frayed snapped wire. Pulling the wire with a pair of pliers released the seat back. I pondered a wire patch, but my numb fingers and toes persuaded me to wait a bit. Better just order the right stuff. Do it once, and do it right.

Anyway, I'll grab some photos for posterity next time I get in there.