The old owner cleaned it with paint thinner witch cause all the brown plus didn't use it for 2 plus years and just left it seat with the cover over it her is another pic
Some people don't deserve to own a boat. I would find a local Upholstery shop and just see what they say. They can copy the patterns from the old seats since there not all torn up.
Looks like the pain thinner removed the protective coating on the vinyl and those stains may be set in. Have you done anything to them yet. Maybe try going over it with mineral spirits or acetone? If you don't want to replace the seating (which you may have to to get it looking as new as possible), you may want to try those and then heavily coat it in 303 or some other protectant with multiple coats in an attempt to try and restore them. Good luck. Keep us posted with updates.
It's time for new vinyl. Look at it this way now you can design it how you want it. I would go with some diamond stitch accents something like the tige boats do. I don't own a tige but their interiors are nice. Good luck man. Also a 2003, if left outside with cover and not garaged would be hammered by now anyway. My 04 was jacked from being outside so had it redone and park it in garage. Good luck
I'm in the process of sending skins off to Viper Customs in Tennessee. It's a lot of work to strip the skins and re-install, but It'll be worth it. For a turn key job you're probably looking at $5k.
I had an 02 and stripped it down and did new carpet and vinyl. Was not that hard either. Check out the malibucrew or shoot me a pm , ill try to find pics of my build. The carpet was cheap, vinyl cost me about 3500 from a local shop