Probably Krause error. I checked Schon catalogue and they lists only K-N (CuNi) under 5$ 1991 coin. The similar 50$ coins were silver, also some coins from the series were issued with denomination 10$ and this is also silver.
I see in Numista coin “Otter” is created twice: CuNi and Silver. Not sure but I guess this is also error based on Krause.
Status changed to Solved(Antonio Junior, 13 Apr 2026, 15:00)