Nick, you might also want to look at Nigel Gatherer's site. He has some material on the people you mention.
Also, a recent article on Iain MacKintosh (by me - BLUSH!) can be found at href=http://www.folkworld.de/15/e/iain.html>FolkWorld. If you think I can help you further, eMail me at skw@worldmusic.de.