I've seen this car in person and it is Drop Dead Gorgeous!
As Chryco stated, this car is in fact a 71 ragtop that was built as a 72 for the TV show to "promote" the next model year's car. Just think of it like the use of the Next Gen Camaro in the Transformers movie - a "You can't buy it, but here's a sneak peak" sort of thing. Difference is Chrysler killed the 72 E-Body ragtops. Remember, TV studios do all sorts of strange things that add to the collectabilty of certain cars - think of all the "71" Cuda converitbles built for Nash Bridges - how many were really 71 Cuda's? This is one of those instances where the car is desirable not because it was restored to factory correct but rather built to TV specs.