I think you will find out that this is a 78 instead of a 77, judging from the fisher t-tops and the interior. The Y82 will not appear in the Vin or on the cowl plate. Phs, build sheet or original window sticker are the only ways of deternining a Special Edition car. Are the factory door stickers still on the driverside door? If they are, these will give you the month and year of the car and help you determine whether it is a WS6, providing it is a 78.