According to the Internet source given below, Leonard von Call was Austrian guitarist and composer, and a contemporary of Giuliani in Vienna.

Websites:
	Leonard von Call ( 1767 - 1815 )	Brief biography by www.earlyromanticguitar.com

Recorder Sheet Music

Trio in G Minor Op.31. (D/A/T) Score and Parts. Arr./Editor: Ulrich Herrmann Publisher: Heinrichshoven's Verlag (N04531)

Quartet in F Major (A/A/T/B) Score and Parts. Arr./Editor: Ulrich Herrmann Publisher: Heinrichshoven's Verlag (N04464)