Manuscript.
Two leaves [19] appear to have been glued together at early stage: some drawings (e.g. a cock and a dragon) can be recognized.
There is no certainty about the author, but since Gregorio wrote in the Florentine dialect and Leonardo, as a clergyman, in Renaissance Latin, the former has been concluded for the Sfera manuscripts.
Toponyms extracted from illustrations.
Place names appearing in the body text listed before the ones in illustrations.
Two unnamed islands below two named ones ("Canaria" and "Lancdato" on page [45] (= page 14 of the 2nd pdf).
Picture of a ruined tower on page [39] (= page 8 of the 2nd pdf). Text on the same page says it is "Tor[r]e Mabel".
Picture of two dragons between cliffs cover most of the page [44] (=page 13 of of the 2nd pdf).