Chris, The GS was an option, not a separate series, so no information was found in the VIN, all Rivieras had a VIN starting with 494. Maybe the Sloan Museum can help you out when you tell them your VIN so they can check if this was for a documented GS car. But the car should have the Star Wars air cleaner that came with the GS option package, and of course GS emblems. Strange but true: the GS option code doesn't appear on the Data Plate found on the fire wall under the bonnet.
