Apograph manuscript containing the Discorso and six scenarios discovered at the Bibliothèque Nationale de France (is part of a "Recueil factice" attached to the Departement de la Musique's collection of librettos).
According to Irene Mamczarz (Introduzione, pp. XI and XV-XVI) the first and second part of the Discorso were written between 1721 and 1722; then, in 1725, they were corrected and the dates updated. Riccoboni continued to work on the manuscript adding other pages between 1726 and 1729, and yet more pages after retiring from active theater. In 1743, he corrected again the second part of the manuscript, updating the dates. Only in 1743, were the scenarios added to the collection.
Discorso sulla commedia all'improvviso e scenari inediti, ed. by Irene Mamczarz, Milano, Il Polifilo, 1973. The Discorso, which opens with a dedication to Ludovico Antonio Muratori, is on pp. 1-34, and contains some observations on acting.