Sor’s Theme and variations [op. 3] were first published in Paris in about 1804-1810 and therefore most probably date from the time when Sor was still in Spain, that is to say from before 1813.
The work was later adapted to become Sor’s op. 12, dedicated to Kalkbrenner.
This edition comes from the new 2019 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.