I decided to use FX-100® Fire Retardant Coating on the seatback. An 8 oz. sample bottle from the company would do two seatbacks. You can read more about it on the web at
http://www.flameseal.com/fxdesc.html
Later I put a coat of Rustoleum Black Texture paint over the FS-100 to tone down the shiney appearance of the fire retardant and hide manufacturing imperfections in the resin.
The FX-100 seemed a nice way to offer fire protection and keep away from gluing some sort of material to the seatback.
I performed a propane torch test on a scrap piece of fiberglass as was shown on their website. I got the same results as the manufacturer.
