16th Century Geometric Perspective Illustrations
Found at BibliOdyssey, a collection of mathematical illustrations found in an obscure paper manuscript.
The album of geometric and perspective drawings (Codex Guelf 74. 1. Aug. fol.) from the 1500s is available online from Herzog August Bibliothek in Wolfenbüttel.
It consists of more than thirty watercolour sketches of polyhedra^ or, as the Latin title on one of the images above has it, perspectives of the regular solids (a standard descriptive name, originating with Plato and Euclid).
More information and examples can be found at BibliOdyssey here