I saw the thread and think that the overstamping is significant to a degree. It should be listed as a different variation of the unstamped chip and will carry the same TCR number. It is possible that it is not a cancellation but an overstamp for a different purpose. On the other hand, we may look at this type of overstamp as a cancellation of the original condition, resulting in a different chip. It may have been used by a different owner, a different game or a different casino in another state.

Either way, it is a fairly common chip and in my opinion should carry the same value, with or without the "W" or "WC". Hope this helps.