1898, 1¢/15¢ Color changes overprinted "Ultramar". Without gum as usual, each handstamped in blue, exceptionally bright and fresh, F.-V.F., exceedingly rare with No More Than Two Examples of Each Stamp Believed To Exist.; with 2003 Sismondo certificate. Scott No. 279S//284S  Estimate $600 - 800. The "Ultramar" (Overseas) overprint was applied by Portuguese postal authorities to foreign stamps received from the U.P.U. in Berne before redistributing those stamps to the post offices in their overseas colonies. $0 (Image)