Check out this 550 Barchetta.... Apparently it is NOT the standard item but a special order for the Sultan of Brunei made and delivered some time BEFORE the introduction of the 448 cars! Mechanicals are unknown but you can tell the cars apart by the absence of rear ''lip'' at the trunk edge, the absence of the protuberances behind the 2 rollbars and the standard 550 coupe fuel cap instead of the special polished silver one on the production Pininfarina Barchetta. Given this guys history with special orders I'm sure that this wasn't just a chop job on a standard Maranello but the car was engineered properly from scratch by Pininfarina. See, this guy never had to wait for cars to be introduced to the market he could just order whatever felt like owning
http://www.geocities.com/sul288us/#6