20 Balboas Simón Bolívar

Panama issued this series under the administration of Omar Torrijos, whose government used it in part to project nationalistic prestige during the years of intense negotiation with the United States over Canal Zone sovereignty — talks that would ultimately produce the Torrijos-Carter Treaties of 1977. At 129 grams of sterling silver and 61 mm across, these were never intended for circulation; they were collector pieces sold through international channels to generate hard currency.

KM#31 is frequently encountered with spotting and milk spots inherent to the planchet preparation of that era, a problem endemic to large-format silver issues of the 1970s across multiple mints.