600 Escudos

The Banco Nacional Ultramarino served as the note-issuing authority across Portugal's overseas territories rather than the metropole itself, and by 1959 was still printing for multiple African and Asian jurisdictions simultaneously — which is why De La Rue maintained distinct plate sets for each territory's issues. The 600 Escudos denomination is an unusual unit, not part of a conventional decimal or dyadic series, and its selection likely reflected a specific monetary-supply calculation rather than any standard progression.

P#45 is scarce in higher grades; the paper stock used across this BNU series is known to brown and soften under tropical storage conditions, which was the practical reality for most of the currency's working life.