This waltz is said to have been a favorite of Lars Nilsson (1815-1899), a fiddler who eventually became known as “Lasse in Lyby” for the town in Skåne where he spent the second half of his life.
It’s unclear if he wrote it or if it was something that he played so often that it more or less became his tune. You can read more about him here (in Swedish).
If you’d like to play it too, here is sheet music complete with suggested chords (just right-click to save and print the image):
By the way, if you happen to play with a string quartet, The Danish String Quartet has a lovely arrangement based on their beautiful recording. They sell the parts here.