Where to find seat for old Manatee

I came across an old, dark green LL Bean Manatee kayak. It is about nine feet and four inches from point to point. It was damaged in a storm. It has a black, plastic back rest but no seat. In an effort to try to find where I could find another seat, I called LL Bean and they said they no longer sold kayaks of that length with those dimensions. Can anyone point me in the right direction? If there are other measurements you would need, to answer the question, I’ll try to provide them. Thanks

The manatees I know all prefer couches.