There is a rod that goes from driver side to passenger side and then in the middle of your seat where there is a support it runs through a rubber grommet (see
www.ClassicParts.com item #28-911) to hold it up/in place. I have several seat rods if you send me a PM we can discuss. The reason why you don't see them for sale is they are 4' long and hard to ship. I think I have about 6 of them laying around. They came with the seat frames from 1951-1955 1st series. Maybe I could fold it and then ship it? Hmmmmm.