I wonder if there was a touring option for the n23?

I had the same thought. Somehow I doubt it, I've never seen anything before to suggest it. You never know though!

I've just checked the fiche for the nc23 and its on there as well under F15 It also mentions model numbers as CBR400RG - RH - YA and looking around the fiche it is for the early Aeros as well as the later models such as the Triarm. So while the picture on that site is not wrong to be in there being a cbr, the model number it gives in the parts list (RRK) is wrong for that seat, just got to be careful its the right model you buy for.