Added the below image and info to the 16th Century Trombone History Timeline. The artist, Cornelis Court, was well known for making engravings that were copies of pre-existing artworks. In this case, the engraving is after a work by Flemish Renaissance artist Frans Floris. The image, which is obviously symbolic, features a relatively small-looking trombone hanging on the upper right area of the wall. It is nearly impossible to tell, and artists are often less than literal, but the instrument could be an alto trombone. (Compare it proportionally, for example, with the other instruments nearby.)
1565—Musica, an engraving by Dutch artist Cornelis Cort from a series called the Seven Liberal Arts (after works by Frans Floris) includes a small trombone hanging on a wall in the background (see facing image; public domain) (Burgers 99).