Seat cushion replacement
The bottom seat cushions on our 1995 Ford Sportsmobile were worn out. They were very uncomfortable. After talking to an auto upholstery guy, I decide to find out if there was replacement foam. I found out that I could get replacement foam for this year through Horizon Ford in Seattle, WA at the best price. Pulled the seats out and removed the seat bottom and then the seat upholstery. Then swapped the old with the new foam, carefully put the upholstery back on and reassembled the seats. The drivers and passenger seats feel much more firm now.
So, if your seats are feeling mushy and not comfortable anymore, it is most likely the seat bottom cushion and for $200 you can replace both bottom cushions.
Watch the Youtube videos from theseatshop.com to get an idea of how it is done. They sell foam and upholstery replacements for >1997 Fords.