100 Francs - Rainier III Piedfort Essai

Piéforts are double-thickness trial strikes produced for official presentation and archival purposes — Monaco's mid-century issues of this type were distributed in small quantities to government officials and the Monnaie de Paris's own reference collection. The 1956 date places this squarely in the period following Rainier III's 1949 accession, when the principality was actively renegotiating its monetary relationship with France under the Franco-Monegasque treaty framework.

Surviving examples outside institutional hands are genuinely scarce.