"Z AVP 999 CO" is likely part of an inscription something like "1 OZ AVP 999 COPPER" - in other words, one avoirdupois ounce (not troy ounce, since it's not precious metal) of pure copper. There wouldn't be enough gold in the gold plating to reduce the .999 purity of the copper.
There are plenty of replica-coin-makers who produce such things. As the 1933 Saint Gaudens $20 never officially existed, one could even argue, from a technical legal perspective, that it isn't even a "counterfeit", but a "fantasy coin".
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis