We offer The Best of the Stamp collecting true gems of Postal history Inverted Centre Stamp Liberia Scott C69v,

MNH. 1952 50c dark blue & carmine Coast Line Map

According to Sellinger, more than 200 exist.

Some stamps used to require a second or third manual feed through the printing press after changing the ink in the press. When the sheet was accidentally fed upside-down for its second passage through the press, an inverted centre would result.