In addition, four new stamps of the same design but with different colors and overprinted with the UPU in a horseshoe design were also overprinted.  And therein lies one of the strange turns of event of this war.  The year before, on September 18, 1880, a Chilean warship had stopped Pacific Steamship Company’s ship “Islay” on the open sea, and confiscated several cases of currency and postage stamps that Peru had previously ordered from the National (American) Bank Note Company. 
 
The stamps, featuring a grill and UPU overprint in a “horseshoe” design, were stored away in Lima for over a year, and then also overprinted with the Chilean coat of arms.  On December 5, 1881, Chilean administrators of the post office in Lima began selling the Peruvian stamps that had been overprinted with the Chilean coat of arms.   Printed: 95,000 of the 50 centavos, 48,000 of the 1 sol.