I guess your question and my answer were among the 200 posts that were dumped.
You questioned if the double stamped chips were salesman samples.
I say no. If it was my company, I would not want double stamped chips being shown as an example of my products.
However, I do not think they were never shipped to the 633. Many runs of hotstamped chips come out with a number of double stamps and other errors.
When chippers bought out Mason and TK Speciality Co inventories they got boxes of error chips. Saito wrote an article iding error chips in the TKS inventory. Other chippers are now selling them as real error chips. Maybe they are but they were never shipped to a casino.
I did not say the 633 is rare only that I did not have it. I have seen quite a few others like it.

The scanned "error chip" from the 633 is a different font than any other 633 chip, and the obverse is blank. I have seen many of these. They are all blank on the obverse and all I have seen are UNC. I think an employee carried them out.