Older (1990s?) yellow fiberglass boat seat from a WEST Marine inflatable made by Achilles. It is 31.5" long and 9" wide. There is cracking on the ends, but I am convinced the seat is structurally sound. I bought it as a spare and then sold the dinghy.
THe dinghy was Achilles red, hypalon, with a plywood floor FYI.
Price: $35 + USPS shipping (it weighs 4.5# packed) My zip is 55803