Hi mate, thanks for that I just looked up that part number and I have that seat new with the drivers back rest up in my shed from when I had my roadster, but I didn't like the way in dropped me lower to the ground and further forward compared to the stock seat. My dealer when I rang I bet just gave me a price off the top of his head from the last one they sold (mine back in 2010) they haven't sold a new rocket since.
This is a link to a seat I found and it looks like it has a wider passenger seat and not as
Low for the rider? It looks like the original classic seat Do you know if they are any good?