The map can be found at http://upload.wikimedia.org/wikipedia/commons/f/fc/1502_Cantino.jpg (download the full resolution version). Instructions to create a map theme from it are at http://techbase.kde.org/Projects/Marble/HistoricalMaps. The projection chosen here looks similar to Mercator.
This one is done already but needs a nice legend.
I'll upload the current state to GHNS. We can still improve the legend in future updates.
SVN commit 1356042 by nienhueser: Add 1502 Cantino historic map theme M +10 -0 maps-4.5.xml WebSVN link: http://websvn.kde.org/?view=rev&revision=1356042