I know better than to type from memory. What memory??
It is a clay chip made at Burt. Ewing hotstamped them which accounts for all the error chips.
It was made between 1966 and 1970. Ewing sold his last chip in 1970. I got this information from Ewings long time assistant. I went to see Ewing in 1995. He was dying and did not have much memory. Could not answer much, he rambled a lot. His assistant was now his nurse/housekeeper. She was caring for Ewing and his wife.
The house was full of stuff from the business and casino stuff collected over the years. It was piled everywhere. It was a small 4 room house and the only place to sit down was the kitchen. All other space was full of "stuff."

I wrote a few lines in a Gaming Times article a couple years later when Ewing died. I tried to find the housekeeper with no luck. The Ewing chip records would have transfered to GGS when he sold the mold to them.