The original Hypersilver wheels were part numbers:
And the 2001-2002 Chrome Shadow versions were:
Both sets of wheels were cast with part markings matching the Hypersilver wheel part numbers. To add to the confusion, they have eerily similar part numbers, too.
The question of the day is: what are the 2 ways (yes, there are 2) to tell them apart? How do you know if you have Hypersilver or Chrome Shadow?
10/21/2015 UPDATE WITH ANSWER:
The most obvious way to tell if Style 40 wheels are Chrome Shadow (2001-2002) or Hypersilver (1999-2000) finish is to look at the inner barrels. They are black on Chrome Shadow wheels (the base color) and gray on Hypersilver wheels (their base color).
But, the second way to tell is that Chrome Shadow wheels actually have a small decal inside the center bore that says "CHROME SHADOW". It is usually covered by the Roundel center cap. Here are some poor quality camera phone pictures of the wheels that came off my S52, apparently all 4 were Chrome Shadow. They did not match well (at all) front to back, so I was expecting to find Hyper Silver in the rear and Chrome Shadow in the front. But I think the variation in Chrome Shadow can be and is pretty significant. I am having all 4 wheels refinished and getting new tires, and will write a separate post on that when I get them back.