OK, just clarifying a few things. If a muscle car was sold NEW at Mr. Norm's Grand Spaulding Dodge, it was dyno tuned before delivery. The new owner was also enrolled in the Mr. Norm's Sport club. Given that fact, every car was given a little special treatment and would have been more likely to have been delivered NEW with aftermarket tachs, wheels, or any performance upgrades possible that were typical day 2 upgrades anywhere else, even though it may not have been called a GSS.
There were no additional fender tags to denote these changes from the dealer.
I am not sure if there were even enough available options on a 69 Dart to warrant it having more than one. If it has three, let us know what is on them. Is the car a Swinger 340 or a GTS 340?