Monterey RM 3500 GT Spyder Prototype

With Monterey RM auctions coming i have some issue with Maserati 3500 GT Spyder Prototype’s description. http://www.rmauctions.com/lots/lot.cfm?lot_id=1067923 RM states that: “One of a believed three Vignale-bodied prototypes” But of all Convertible prototypes and one-offs, there were 5 Vignale creations, including one Special and 4 prototypes: I have contacted Maserati Classiche and awaiting reply 3500 GT…