I located a few options to replace seats, but I am not sure which is best, if they will fit. I checked part number for my 1997 Sea Doo Challenger at seadoopartshouse.com, which did not match 1996 Speedster seats I found. Does anyone know if these seats are interchangeable? They would need recovered, unlike some on Ebay from a 1999 challenger 1800. I don't think backrest would fit, but the seats might fit. Any advice on building, buying, and recovering would be appreciated.