I just added the following image to the 18th century Trombone History Timeline. I also added it to the HubPages articles Angel Trombonists Throughout History and How to Hold a Sackbut: The Grip of the Early Trombone in Pictures.

1725-30—Vienna, Austria: A fresco by Johann Michael Rottmayr in the Karlskirche (St. Charles’s Church) includes a trombone-playing angel (see below image; public domain).