Don, one source I've used for issue dates has been Larry Hollibraugh's renocasinochips.com website.
But I've never bothered to ask Larry what his source has been.
As for the Harvey's chips that we've been talking about, my understanding of the earlier large key molds is they were first issues in 1970, with the house molds coming in 1973 and later.
And the brass-cores coming out in 1986.
I've always assumed the Chip Rack included issue dates.
But I guess I'm mistaken about that?