1/2 Rial Saidi

Muscat and Oman's currency board issued this series in 1970 — the same year Sultan Qaboos deposed his father Said bin Taimur in a palace coup backed by the British. The timing matters: Said had deliberately kept Oman isolated and underdeveloped, and the new administration moved quickly to modernize, including replacing this very note type with a new issue under the renamed Sultanate of Oman within months of the transition.

Bradbury Wilkinson printed the series at New Malden before the political change made it almost immediately obsolete, which accounts for the relative scarcity of used examples in the half-rial denomination.