This map appears to be from a period early in the exploration of the New World, when the Western coasts were not known, or not well known enough to appear in full. Later panels showing Asia indicate a crude knowledge of the geography of anything east of Europe.... any thoughts on the date? Can it be made out in the text?
I knew I recognized that map. It's Diogo Ribeiro's third world map from 1529.
Ribeiro made the maps (not this one, different maps) that were used on Magellan's voyage around the world. Ribeiro's background is somewhat obscure, he initially worked as a pilot for Portugal sailing on the Indian trade routes before switching his loyalties to Castille in sometime before 1518. He was later very involved in treaty negotiations in 1524 between Castille and Portugal over the location of the Moluccas, spice islands that were worth quite a lot of money. These maps were a significant part of the negotiations over the Treaty of Saragossa, which was ratified in 1529.
Unfortunately, that's about all I know about that, early modern treaties are really not my specialty. There's an interesting chapter on the negotiations in Jerry Brotton's A History of the World in 12 Maps as well as a detailed facsimile of that map.