i have a 2004 high octane fr i was seeking to purchase a scott tpu neoprene chainstay protector as they don,t make a specific one does anyone know which one might fit it would have to be abouy 4 and a half inches wide

Neoprene protectors don't last very long IME!
You'd be better off using a section of old tyre/innertube and some cable ties!

tube and cable ties is where it's at!