Watch List notes:

(g) Montenegro, Nikola I Petrovic-Njegoš (1860-1918), 20-Perpera, 1910 SS, Vienna, edge lettered, 6.79g, 12h (KM 10; Schlum. 2; Fb. 2), lightly wiped, otherwise lustrous, a bolder very fine, very rare, 40,000 pieces reportedly struck