Short answers, pulled from the story.
Alberto Cantino stole the Portuguese world map in 1502 while working as a horse trader for Ercole I d'Este, Duke of Ferrara. He paid twelve golden ducats to acquire the chart and smuggled it across the Mediterranean to Italy.
The Cantino planisphere introduced a new method called the latitude chart during the second half of the fifteenth century that placed locations according to their actual latitudes instead of relying on magnetic courses. Two circles formed the foundation of its rhumb line system with sixteen equally spaced points marking each circumference.
Pedro Álvares Cabral explored the Brazilian coast in 1500 and his fleet's findings appeared on this manuscript alongside Gaspar Corte-Real who visited Newfoundland in 1500 and 1501 under King Manuel I of Portugal. The map also shows the southern coast of Greenland studied by João Fernandes Lavrador in the late 1490s.
The geographical information on the Cantino map was copied into the Italian-made Canerio map shortly after its arrival in Italy which became the primary source for Martin Waldseemüller's highly influential wall map produced in 1507 under Rene, Duke of Lorraine. Other maps depicting the same area include those calling it Parias or Asie partis based on Amerigo Vespucci's Four Voyages.
More than two centuries passed until 1859 when the palace was ransacked and the Cantino Map disappeared from official records before Giuseppe Boni found the document in a butcher's store in Modena that same year. It now resides permanently at the Biblioteca Estense where scholars can study its unique historical information about maritime exploration.