Way back in the early years of this website—2009, if you can believe that—I made a post about a black and white image whose origin was a mystery to me. It turns out that the image, shown below, was an engraving of a detail from a painting by Belgian painter Willem Geets. The original painting is shown at the bottom of this page and can be found in historical context in the Trombone History Timeline (19th century, 2nd half). As my art professor friend suspected, it is a relatively recent image intended to look old!
1892—Belgium: Willem Geets paints Puppet Theatre at the Court of Margaret of Austria (Mechelen 1515). It belongs to a series of paintings by Geets, depicting, 500 years after the events, the young Prince Charles as he was raised in Mechelen at the court of his aunt, Margaret of Austria. The picture includes a trombone (possibly an alto trombone) performing in a small wind ensemble accompanying a puppet show (Museum Hof van Busleyden). See below image; public domain.