solo seat cowls normally sell on ebay I've seen the rear seats hang on a bit if its the touring one with handles they fetch a good price.but why not wait to see how the sale of the bike go's it could help you get the price your looking for
Offer it to the new owner for a price, save him pissing about on ebay trying to find one to match.
I did this when I sold a Z750, I took off all the extras and offered them seperately.