This is the seat:
https://www.quadratec.com/products/24270_1XX_PG.htm
Still in nice shape but for two things. One, a small metal rod poked out the side of the lower. Doesn't seem to cause any issue but it did punch a small hole in the seat. Two, whatever supports the lower back seems to have collapsed. You can see how the covering no longer is pushed out. This is likely repairable but I simply bought a new seat.
Free to anyone who wants it.