Sor’s Trois duos faciles et progressifs by Sor for two guitars, op. 55, were published in Paris in 1833-34. They are more teaching pieces, simple and charming.
Duo 1 is an Andante followed by an Allegretto. Duo 2 is also an Andante followed by an Allegretto. Duo 3 is a theme and variations followed by a waltz.
The full title was Trois duos faciles et progressifs pour deux guitares composés et soigneusement doigtés par Ferdinand Sor (Three easy and progressive duos for two guitars composed and carefully fingered by Fernando Sor).
This edition comes from the new 2020 second edition of Sor’s New Complete Works for Guitar edited by Brian Jeffery. The Introduction and Index to the entire series can be seen here on this site.