When I reread the ChevyTalk post I realized that Carl and Verne have two different opinions on the matter of sharing VIN tag info.
That said, since the vehicle in question was a Super Sport from the factory, it makes sense that "SPORT" was used on at least the 62 (and it appears also the 63) Super Sports that were assembled at the Atlanta plant. There is some question about the "X1" but that doesn't have much bearing on the topic. Some speculate that it might have meant having a RH mirror on the door, that sort of thing.
I look forward to making the trek down to Springfield MO in the coming weeks to take in all that is RussC and his many finished projects
.