I recently added the below caption and 3 images to the Trombone History Timeline (16th century). The instruments are highly stylized, but I think there’s a good chance they represent a trombone, cornetto, and harp. Special thanks to Suzanne van Os. Below those 3 images (below the horizontal line) is another visual representation of Belshazzar’s Feast that includes trombone.
1600—Dutch artist Jan Harmensz Muller (or one of his followers) paints Das Fest des Belsazar (Belshazzar’s Feast), which includes an ensemble of what appears to be trombone, cornetto, and harp, performing from a balcony. The trombone is held awkwardly and the proportions of the cornetto are also unorthodox (see detail and full image, first two images below; public domain). A very similar image, a black and white print, is likewise attributed to Muller, sometimes at a slightly earlier date (1598) (see third image, below; public domain).
c. 1630—Antwerp, Belgium: A painting on the lid of a harpsichord by Franz Francke (1581-1643) depicts Belshazzar’s feast. A trombone is pictured performing with string instruments and a keyboard (see below image; public domain) (Munich, Bayerisches Nationalmuseum. Cat. No. 174; Hirt, Stringed Keyboard Instruments 263).