I vaguely recall seeing some silver Krugerrands somewhere. Coincidentally two Krugerrands are the gold coins I have owned the longest, from when I was a kid.
Since I was 12 my grandfather gave me a St Gaudens Double Eagle every year till I was 21
Sadly I sold them all in 1980 cause I needed the money for as much downpayment on a house as I could get
I kept some 20 francs I had copperpolished as a kid , they retoned nicely and they are obtainable at meltvalue anyway
If this advertisment was in Europe I would presume a rip off with extremely small medals
or VF silver coins from 12 countries ( the EU started with 12 I think and I saw a set advertised from the EU founding countries )