PMG 15 Choice Fine (1913679-007).
P.28a.
This is the second highest grade! Alphabet O.1 - number 531, an extremely rare type in Alphabet 1, this is the 13531st banknote issued. Only one other example is referenced in the PMG population database to date (Top pop: PMG 25).
PMG 15 Choice Fine (1913679-007).
Exceptional and extremely rare, issued and first series. VG to VG+.