I found Vals till Birgitta av Wikand Hans on the Boda Spelmanslag album 50 år. 
 
  https://www.youtube.com/watch?v=sFmyINITEWc
 
When I first heard this tune, I couldn't stop listening. Unfortunately, I couldn't find the notation anywhere,  which meant transcribing, at which I am very slow. I called on fellow Peascods band members Joel Edelman and Lisa Robinson, and Washington's Spelmanslag member Julia Borland, and among the four of us we came up with a transcription. Joel and Lisa did the chords.
 
It's a little tricky for me to play in A on the English concertina, but I really like the sound in this key. I'm also providing it in G.
 
 Dottie Beck