Hi, Martin - "Twa Bonnie Maidens" is here (click) in our database. There's a MIDI of the tune down at the "Click to Play" link at the bottom of the lyrics, and you can download the MIDI with a right-click of your mouse.
There's another website listed in our "links" page called Yet Another Digital Tradition (click). they have out tunes in various formats, including a GIF you can print out.
I don't have the chords, but maybe somebody will post them. Yup - Pene did, above)
-Joe Offer (e-mail sent)-