Added the below image and caption to the 16th Century Trombone Timeline. Not only is it an unusual visual depiction from relatively early in trombone history (1550-1556), but it is from the New World. There is another image in the timeline that’s from 16th century Mexico, a fresco in the church of San Esteban in Tizatlan, Tlaxcala, that features a trombonist-angel, but I have not been able to pinpoint a date more specific than the 16th century.
1550-1556—Huejotzingo, Puebla, Mexico: A stone carving on one of the 4 posa chapels occupying the corners of the atrium of the church of the Franciscan monastery of San Miguel, Huejotzingo features 2 trombone-playing angels (see facing image; public domain) (Viñuales and Gant 23; Donahue-Wallace 12).
Gregory Campbell
Great picture-great website also! Keep up the good work!