5 Rupees - George V

Pick 20 belongs to a short-lived series issued under George V that was effectively obsolete before it could establish much of a circulation history — the Government of Mauritius replaced the Waterlow-printed notes with a new series in the 1930s as colonial currency standardization efforts accelerated across British dependencies. Waterlow & Sons held numerous British colonial contracts during this period, and the Mauritian commissions were among their smaller, less technically elaborate jobs.

The watermark is the sole mechanical security feature — no serial number overprinting in colored ink, no metallic thread. Straightforward even by the standards of the day.