Need seat for Walden Paddler

The seat for our Walden Paddler kayak mysteriously disappeared and the company is out of business (so no luck there). If I remember right, the original was a molded plastic bucket seat that clipped in via one strap in the elastic back. I have searched online but all the replacement seats are too low and would need attachment points. Any suggestions on what to do?

See photo for an example of kayak and seat. f2_Walden_paddler_kayaks__400_Southwick_5ac071df32b4a|600x337