Well.... it seems I don't! I should have gone and looked at it while I was writing the post. That is why I said gold....or yellow... or something like that. Turns out, it is only Nickel Azo Yellow. 😃
I have heard the "gold" so much, that it stuck in my mind, but when I typed it, I found I was not sure. Sorry about that! Yeah, if someone actually had the Gold now, I suppose they would try to sell it for a fortune if they were not going to use it themselves.
I just Goog'd it and it said the closest mix for the original is the two colors I have mixed together or the company meant for regular Azo Gold to come close.
I'm not sure why they stopped making it since it was very popular. Maybe it just got too costly or they couldn't get one of the ingredients. It's a mystery and a great shame. Such a beautiful paint. I never actually had my own but my friend who got me into painting decanted a bit of hers into a little bottle for me. it ran out years ago though.