Since I am an engineer, I like to take things apart (to learn how they work and understand their operation)
Since the seatback was ripped open by the airbag, that was the logical place to start exploring,
so I removed the cloth (zipped open the two zippers on the rear side of the seatback and with some effort, removed
the cloth from the foam and frame.
Saved the headrest guides and the cloth, just in case I needed it for something.
removed the foam off of the frame, including springs and other retention hardware and trashed it.
Saved the frame, just in case someone has a damaged frame and eventually I will include it in a scrap metal dump run.
Also removed the blown airbag and wire.
I was surprised to find that the seat back is bolted to the lower part of the seat near the recline mechanism with 4 bolts, I believe they are 14mm head, the same size as the seatbelt buckle attachment bolt. They are *tight* but with the 3 ft steel pipe extension on my ratchet, it was easy to get them off and swap the back of the good seat onto my own seat.
It would have been easier to simply swap the entire seat (only need to unbolt the 16mm head bolts on every corner of the rails of the seat and unplug the buckle switch and the side airbag, but the "good" seat that I picked up was also dirty, in particular the lower seat, the back is in decent shape. So I went through the effort of swapping the good back onto my original and much cleaner lower seat and re-installing the seat into my car.
The resulting offer is - if anyone needs a complete working lower seat (think of the complete seat minus seat back and minus buckle) or head rest, then contact me. The seat slides and locks on the rails and the turn knob raises and lowers (tilts) the bottom seat and the handle for the seat back recliner works as expected.