I added the below caption and image to the Trombone History Timeline (18th century). Austria is one of the most important locations for trombone in the 18th century, and this is reflected in iconographhy of the period.

c. 1748—Wilhering, Austria: Decorations surrounding the organ in Wilhering Abbey feature a trophy of musical instruments that includes both a trombone and a cornetto (see detail and full image below; public domain).