Watch List notes:

Philippines, Culion Leper Colony (1906-30), second issue, Pesos, Manila (23), 'Bureau of Health' issues (12), in aluminium, 1920 (10) (KM 15); in cupro-nickel, 1922, with countermark, scarce only 8,280 pieces struck (2); third issues, 1925 (11), the first somewhat corroded as expected, the rest generally good fine to good very fine, all scarce, an unusual offering (23).
It was discovered that the aluminium issues struck in 1920 degraded more quickly than anticipated in the warm tropical climate. The problem was rectified in the coinages of 1922 and 1925 by use of a cupro-nickel alloy
Estimate: £150 - £250