Convertible window

you tried going to a boat shop yet? they will replace your window cheaper probably. My dad got a whole custom made canvas top with a rear window for a little under $300. Tak in mid this this a 23ft boot and they even made windows that zipped into the sides. If I recall correct, they added his back window for like $60-70. There should be someone nearby a lake or somewhere that will do it for you. Just call the local boating shop, they should know who makes custom covers.