1857, Isabella II. ½r. blue vertical strip of four with close to good margins with parilla killers on registered cover addressed to "Vicente Costa farmaceutico" in Tossa, with clear cds. "AGUADILLA PUERTO RICO 9 FEB 62", straight-line "CERTIFICADO" and "CADIZ" and "BARCELONA" transit marks alongside, the first stamp was originally affixed around the envelope, now stabilized by paper strip thus fully visible at the front, in overall very beautiful and appealing condition, being one of the most important letters of Puerto Rico and the only known registered letter recorded, detailed certificate Graus AIEP
