Keith,
Here's a screenshot courtesy of The Chip Guide. Take note of the metallic gold printed ring around the edge of the 1st edition chips. The majority of the first rack had the same design that included metallic gold plus the CMYK ink. There were also chip runs that had a spot color green printed on top of the gold versus others that used the CMYK ink to print the type. The process color (CMYK) was difficult to keep a uniform shade and registration while having the main image match the approved artwork.

Metallic gold ink was a challenge to keep dense enough to have the metallic effect after lamination but still laminate properly. Being on the edge was a concern for proper adhesion of the inlay to the slug. There were many ink tests / adhesion tests with metallics over the years. Most of the tests were done with a chip color that would not be used in the final production.
This is the result of the many tests made back in the late 80's & early to mid 90's. This one's from late 1994 early 95. Gold ink was dialed in and the formulation was used for many years afterwards.

If you have any other questions feel free to ask.