Charley, I'm going to throw mud on your car by telling you a story. One that happened to me.
Back in 1990, I purchased a new Chevy S-10 Blazer. I wanted a black exterior with gray interior S-10 but it had to have a manual transmission. The dealership didn't have one in stock so after doing a network search, they found one up in Bakersfield (about 150 miles away). I put a down payment on the truck and when it came in a few days later, it was exactly what I wanted EXCEPT it had the butt-ugly (IMO) aluminum wheels! I was hemming and hawing about getting the truck with those wheels and was trying to make a deal to get the price down, when the sales guy said he could swap out those wheels for the Rally wheels I originally wanted. I asked him how long it would take to get the wheels and he said he could just swap them out with another truck he had sitting on the lot. Not only did he swap the wheels, but he also threw in the rear spare tire carrier and cover to cover the price difference between the aluminum wheels and the Rally wheels. I was satisfied. (By the way, that was a GREAT truck!! 4.3L V6 with the Getrag 5 speed manual transmission. I ran it for 13 years before trading it in on a 2003 Toyota Highlander.)
I'm not saying this is what happened in your particular case, but as we know, a lot of things can and do happen at dealerships. Your Rally wheels may not have been what the original owner cared for so they may have swapped out the Rally wheels with the XT wheels. And why aren't they body color? Because perhaps they came from a Cortez Silver car that was also on the lot at the same time? This would explain the color and all 5 being the same date. As for the funky caps, I too believe that was done by a prior owner (MAYBE the dealer but highly doubtful) since the factory wouldn't have done it.
Again, not saying this is what happened, but it's one possibility. Unless you can find absolute proof one way or the other, you'll never know.
Ed
