Adam61-
So i have a similar situation. I just got a 52 chevy 1/2 ton. Turns out at some point, some cute little mice decided to nest underneath the seat. I've got some time as a detailer so i've treated similar oder's in other vehicles. in this case, i vacuumed everything out, treated the metal under the seat and re-painted. i can still smell it. Although i see people recommend fabreeze or other industrial cleaners, my advice would be to recover the seat. take it down to the frame and start over. quite frankly, no matter what chemical you use, padding is so thick and there is so much overall material on seats, i doubt you could really clean it enough to completely remove the oder. plus chemicals that are too harsh will most likely damage the fabric....
